Rotor, drive conversion device, cleaning device, wiping device, and liquid injection device

ABSTRACT

A nozzle protecting device  30  of an ink jet type recording apparatus has a cap  46  which covers nozzles of a recording head and a cap support member  47  which is connected to the cap  45  via a spring member  80 . The distance between the cap  46  and the cap support member  47  can be changed by elastic deformation of the spring member  80 . A vent hole  54  is formed in the cap  46 . A valve seat  56  which covers the terminal portion of the vent hole  54  is provided. A valve body  58  is rotatably attached to the lower portion of the cap  46 . The valve body  58  selectively abuts on and parts from the valve seat  56  in accordance with the distance between the cap  46  and the cap support member  47 . As a result, the inside of the cap  46  is opened and closed to air via the vent hole  54.

FIELD OF THE INVENTION

The present invention relates to a rotor, a drive converting apparatus,a cleaning apparatus, a wiping apparatus and a liquid ejection apparatusthat have these apparatuses.

BACKGROUND OF THE INVENTION

As a conventional liquid ejection apparatus which ejects a liquid on toa target, there is, for example, an ink jet type printer which prints animage or the like by ejecting ink droplets on to a page. This type ofprinter has a carriage member having a recording head and a platen whichsupports a target, for example, paper. The recording head has aplurality of nozzles which eject inks. Paper is guided between therecording head and the platen and inks are ejected onto the paper fromthe nozzles. This printer is generally provided with a cleaningapparatus to clean the nozzles in order to prevent ink clogging in thenozzles. The cleaning apparatus includes a cap apparatus having a capwhich covers the recording head, a tube pump to be connected to the capapparatus and a wiping apparatus having a wiping member for cleanlywiping inks adhered to the recording head. The wiping apparatus wipesthe recording head clean by causing the wiping member to slide incontact with the recording head.

The cleaning operation of the printer will be described in detail.First, after the carriage is moved to a position at which the recordinghead faces the cap apparatus, the recording head is covered tightly withthe cap. Subsequently, the tube pump is driven to suck out the inks,which become highly viscous and may cause clogging in the nozzles,together with air inside the cap and discharge the inks outside thenozzles. While the tube pump is driven, the wiping member is placed at apredetermined position where the recording head can be wiped. When thesuction of the tube pump is finished, the cap is moved downward afterwhich the carriage is moved to cause the recording head to slide incontact with the wiping member, thereby wiping the recording head.

In such a cleaning apparatus, a drive source for driving the capapparatus, the tube pump and the wiping apparatus is common for makingthe printer compact. As compared with the driving of the tube pump,however, the cap apparatus and the wiping apparatus are driven only fora short period of time and their timings differ. Therefore, the tubepump is constructed to be driven on the drive force directly receivedfrom the drive source, whereas the cap apparatus and the wipingapparatus are driven via a drive converting apparatus using part of thedrive force from the drive source. (See, for example, Japanese Laid-OpenPatent Publication No. 2000-153617 and Japanese Laid-Open PatentPublication No. 2002-225299.) Those publications disclose printers thatuse a drive converting apparatus which drives the tube pump and wipingmember with a single motor.

In Japanese Laid-Open Patent Publication No. 2000-153617, for example, apump wheel to drive the tube pump is arranged on one side of a gear towhich the drive force of the motor is transmitted. As the gear rotates,the pump wheel rotates with the rotation of the motor to thereby drivethe tube pump. Meanwhile, the wiping apparatus is arranged on the otherside of the gear via a friction clutch as the drive convertingapparatus. The drive force of the motor is transmitted to the wipingapparatus via the friction clutch, moving the wiping member to apredetermined position. The friction clutch is operated intermittentlywith respect to the driving of the tube pump.

In case of the publication described above, the drive force of the motoris transmitted to the wiping apparatus by the friction clutch alone. Inthe case where inks are adhered to a driven gear and the frictionclutch, for example, the weights of the parts to be driven, i.e., thedriven gear and the friction clutch, increase because of the adheredinks. Therefore, the frictional force needed to drive the wipingapparatus becomes greater so that even when the drive force of the motoris transmitted to the friction clutch, the wiping apparatus cannot bedriven.

Japanese Laid-Open Patent Publication No. 2002-225299 discloses theprinter which is provided with a drive shaft to drive the tube pump andthe wiping apparatus. The drive shaft penetrates the center of the pumpwheel of the tube pump. The tube pump is driven as the pump wheel isdirectly rotated according to the rotation of the drive shaft. Thewiping apparatus has a first drive mechanism including a sun gear, acleaner drive lever, a gear holding lever and a planetary gear whichconstitutes the drive converting apparatus, and a second drive mechanismdifferent from the first drive mechanism. The drive shaft is fitted intothe center of the sun gear. As the drive shaft rotates, the second drivemechanism is driven via the sun gear, positioning the wiper to apredetermined position. The first drive mechanism functions tointermittently operate the wiping apparatus with respect to the drivingof the tube pump. Therefore, the drive converting apparatus in JapaneseLaid-Open Patent Publication No. 2002-225299, unlike that in JapaneseLaid-Open Patent Publication No. 2000-153617 can drive the wipingapparatus even if inks are adhered to those parts to be driven.

There was a case where printing defects would occur due to an increasein the viscosity of the ink caused by evaporation of a solvent, such aswater, from the openings of the nozzles, adhesion of dust to theopenings of the nozzles and mixing of bubbles in the ink caused byreplacement of a cartridge, or the like.

To maintain the performance of the nozzles in the best condition,therefore, a nozzle protecting device equipped with the cap, whichcovers the nozzles of the recording head and the tube pump that sucksout ink, and bubbles or so in the cap covering the nozzles, is used. Inthe case where printing is not carried out over a long period of time,the nozzles are covered with the cap, thus preventing the ink frombecoming dry. As needed, the tube pump is driven with the nozzlescovered with the cap, setting the inside of the cap to a negativepressure, so that the ink whose viscosity is increased or bubbles or thelike generated in the recording head by replacement or the like of thecartridge is discharged to the ink tank, thereby maintaining theperformance of the nozzles in good condition.

If the tube pump is driven to set the inside of the cap to a negativepressure as mentioned above, the inks flow into the cap via therecording head and fill the inside of the cap. As those inks wouldbecome unnecessary at the time of performing printing, so-called airsuction was performed to exhaust the inks into the ink tank by the tubepump while taking air inside the cap. Taking air inside the cap wasexecuted while slightly separating the cap from the nozzles.

Recently, the sizes of ink jet type recording apparatuses (printers) arebecoming rapidly smaller and demand for a greater degree of freedom forlocating recording apparatuses is increasing. Recording devices areincreasingly used in a state other than in a horizontal state, and ifair suction is carried by the above-described method under such a usage,the inks would leak from the cap in the instant the cap is separatedfrom the nozzles. As a result, the inside of the recording apparatusbecomes dirty.

To ensure air suction even if the recording apparatus is placed in astate other than a horizontal state, therefore, air release means whichcauses the cap to communicate with air as needed while covering thenozzles is provided. The air release means can release the inside of thecap to air before the cap is separated from the nozzles, so that theinks can be exhausted outside without causing ink leakage.

One example of the nozzle protecting device having an air release meanscomprises a tube to communicate inside the cap with air and a valvewhich opens and closes the end portion of the tube. The nozzleprotecting device is of a slide type whose slider elevates up and downas the carriage moves in the scan direction so that the cap covers thenozzles as it elevates according to the elevation of the slider. Theopening/closing of the valve is executed according to the operation ofthe carriage in the scan direction and air is taken inside the cap asneeded.

However, such air release means needs the tube suitable located and thusmakes the structure of the nozzle protecting device complicated.Further, after the valve is opened or closed by the movement of thecarriage, the inks inside the cap are exhausted by the tube pump.Therefore, the first drive means which drives the carriage and thesecond drive means which drives the tube pump should be drivenseparately, complicating the structure.

The slide type nozzle protecting device makes the space for the carriagein the scan direction larger, which is a factor to enlarge the device.Recently, therefore, an up/down movement type which can make the spacesmaller is becoming mainstream as compared with the slide type. Forexample, Japanese Laid-Open Patent Publication No. 2002-36578 disclosesan up/down movement type nozzle protecting device provided with an airrelease valve.

The nozzle protecting device has a multi-stage rotary cam having aplurality of cams on the same shaft. The multi-stage rotary cam has afirst cam to elevate the cap, a second cam to open and close an aircommunication valve as an air release means and a motor. As the driveforce of the motor is transmitted to the multi-stage rotary cam and thegear of the tube pump, elevation of the cap, the opening/closing of theair communication valve and driving of the pump gear are carried out.And, the air communication valve is opened or closed with the capcovering the nozzles, after which the pump gear is driven to perform airsuction.

The operations of the cap and the air communication valve have nothingto do with the movement of the carriage, and the cap, the aircommunication valve and the pump gear can be driven to perform airsuction with a single motor, thereby simplifying the device.

While the nozzle protecting device disclosed in Japanese Laid-OpenPatent Publication No. 2002-36578 is made simpler, however, it needslarger space for the multi-stage rotary cam so that the ink jet typerecording apparatus is larger.

The drive converting apparatus disclosed in Japanese Laid-Open PatentPublication No. 2002-225299 is comprised of many parts. Accordingly, aheavy load is applied to the drive shaft that drives the wipingapparatus and the tube pump.

That is, a large drive force is needed to drive the wiping apparatus andthe tube pump more reliably. Generation of large drive force requiresthe use of a larger motor. As size reduction of the drive convertingapparatus, is eventually demanded together with size reduction of therecording apparatus, it will become difficult to use a large motor.

In the case where the target to be printed is a thick object, such asCD-ROM, it is necessary to make the distance from the platen to therecording head large. As the wiping apparatus is normally fixed to theprinter, when the recording head is moved upward to make the distancefrom the platen to the recording head larger, the distance between thewiping member and the recording head changes. Accordingly, the slidepressure of the wiping member to the recording head changes, making itdifficult to wipe the inks adhered to the recording head satisfactorily.

For example, Japanese Laid-Open Patent Publication No. 2002-264350discloses a technique for reducing the wiping speed of the wipingapparatus or increasing the wiping ability of the wiping member to cleanthe recording head adequately even if the distance from the platen tothe recording head is changed.

Even with the use of the technique disclosed in Japanese Laid-OpenPatent Publication No. 2002-264350, however, it is difficult tosufficiently wipe and clean the recording head with the wiper when thedistance from the platen to the recording head is changed. Therefore,there was a demand for a technique which would wipe and clean therecording head more satisfactorily with the wiping member even when thedistance from the platen to the recording head is changed.

SUMMARY OF THE INVENTION

It is a first object of the present invention to provide a compactliquid ejection apparatus with a simple structure. A second object is toprovide a liquid ejection apparatus which is unlikely to cause liquidleakage even in usage in a state other than a horizontal state.

To achieve the above objects, the present invention provides thefollowing liquid ejection apparatus. The liquid ejection apparatus has acap, a cap support member, drive means, elastic means and air releasemeans. The cap support member supports the cap. The drive means drivesthe cap support member to move the cap toward a liquid ejection head andcover nozzles of the liquid ejection head with the cap. The elasticmeans intervenes between the cap support member and the cap. The elasticmeans changes a distance between the cap support member and the cap asthe elastic means stretches with the cap covering the nozzles. The airrelease means opens and closes inside the cap covering the nozzles withrespect to air in accordance with a change in the distance.

The present invention also provides the following rotor. The rotor has apartially toothed gear and a rotary member. The partially toothed gearhas a plurality of teeth formed on a part of the circumferential surfacethereof. The rotary member rotates according to rotation of thepartially toothed gear. The partially toothed gear is coupled to therotary member in such a way as to be permitted to rotate within apredetermined range.

The present invention also provides a drive converting apparatusequipped with the above-described rotor. The drive converting apparatushas a drive gear, and a driven gear which engages with the drive gearand urging means. The drive gear engages with the partially toothed gearof the rotor. Teeth are formed around the entire circumferential surfaceof the driven gear. The urging means urges the driven gear toward thepartially toothed gear to transmit torque from the driven gear to thepartially toothed gear. The torque of the driven gear rotates thepartially toothed gear in a direction of engagement with the drive gearfrom a state where engagement with the drive gear is broken.

The present invention further provides a cleaning apparatus equippedwith the above-described drive converting apparatus. The cleaningapparatus is equipped with wiper means having a wiping member and awiper support member. The wiping member cleanly wipes a liquid ejectionhead having a plurality of nozzles for ejecting a liquid. The wipersupport member supports the wiping member. The positioning member of thedrive converting apparatus is coupled to the wiper support member. Asthe rotor of the drive converting apparatus rotates, the positioningmember is lifted up and down to lift the wiping member up and down.

The present invention also provides the following wiping apparatus. Thewiping apparatus has a wiping member which abuts on a liquid ejectionhead for ejecting a liquid and wipes the liquid injection head clean.There are a plurality of positions of action at which the wiping memberwipes the liquid injection head clean. Wiper position adjusting meansadjusts the plurality of positions of action.

The present invention also provides another liquid ejection apparatus.The liquid ejection apparatus has a platen which supports a target, aliquid ejection head which injects a liquid to the target, a wipingmember which abuts on the liquid ejection head and wipes it clean, andwiper position adjusting means which adjusts the position of action ofthe wiping member based on a distance from the platen to the liquidejection head.

The present invention provides a further liquid ejection apparatus. Theliquid ejection apparatus has a platen which supports a target, a liquidejection head which injects a liquid to the target, a wiping memberwhich abuts on the liquid injection head and wipes it clean, and wiperposition adjusting means which adjusts a position of action of thewiping member based on elevation of the liquid injection head.

The present invention also provides a wiping method for wiping theliquid ejection head clean, which ejects a liquid on to a target. Thewiping method includes a step of adjusting the position of action of thewiping member based on a distance from a platen which supports thetarget to the liquid ejection head, and a step of causing the wipingmember to abut on and wipe the liquid ejection head clean.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an ink jet type recording apparatusaccording to a first embodiment embodying the present invention.

FIG. 2 is a perspective view of a nozzle protecting device equipped inthe recording apparatus in FIG. 1.

FIG. 3 is a partly exploded perspective view of the nozzle protectingdevice in FIG. 2.

FIG. 4 is a partly exploded cross-sectional view of the nozzleprotecting device in FIG. 2.

FIG. 5 is a partial cross-sectional view of the nozzle protecting devicein FIG. 2.

FIG. 6 is a perspective view of a cylindrical cam provided in the nozzleprotecting device in FIG. 2.

FIG. 7 is a diagram showing a state before a close-contact portion ofthe nozzle protecting device in FIG. 2 abuts on a recording head.

FIG. 8 is a diagram showing a state where the close-contact portion inFIG. 7 abuts on the recording head.

FIG. 9 is a diagram showing a state where a lever of the nozzleprotecting device in FIG. 2 protrudes outward.

FIG. 10 is a diagram showing a state where a cap of the nozzleprotecting device in FIG. 2 approaches its closest position to a capsupport member.

FIG. 11 is a diagram showing a state where a valve body equipped in thenozzle protecting device in FIG. 2 rotates.

FIG. 12 is a side view of a nozzle protecting device according to asecond embodiment of the present invention.

FIG. 13 is a side view showing a state where the nozzle protectingdevice in FIG. 12 is provided with a partition.

FIG. 14 is a diagram showing a state where a cap support member is moveduppermost in the nozzle protecting device in FIG. 12.

FIG. 15 is a diagram showing a state where a projection provided in thenozzle protecting device in FIG. 12 abuts on an abutment portion of thepartition.

FIG. 16 is a front view of essential portions of a nozzle protectingdevice equipped in a recording apparatus according to a third embodimentembodying the present invention.

FIG. 17 is a plan view of the nozzle protecting device in FIG. 16.

FIG. 18 is an outline perspective view of the nozzle protecting deviceas seen from the tube pump side.

FIG. 19 is an outline perspective view of the nozzle protecting deviceas seen from the drive motor side.

FIG. 20( a) is a perspective view of a cylindrical cam and a wipingapparatus according to the third embodiment as seen from the bottomside.

FIG. 20( b) is a perspective view of the cylindrical cam and the wipingapparatus according to the third embodiment as seen from the bottomside.

FIG. 21 is a bottom view of the cylindrical cam and what lies around it.

FIG. 22 is a front view of the cylindrical cam.

FIG. 23 is an exploded perspective view of the cylindrical cam.

FIG. 24 is a bottom view of a partially toothed gear of a cylindricalcam according to a fourth embodiment.

FIG. 25 is a bottom view of the partially toothed gear of thecylindrical cam in FIG. 24.

FIG. 26 is a bottom view of the partially toothed gear of thecylindrical cam in FIG. 24.

FIG. 27 is a perspective view of a recording apparatus according to afifth embodiment of the present invention.

FIG. 28( a) is a side view showing a gap between a platen and arecording head equipped in the recording apparatus in FIG. 27.

FIG. 28( b) is a side view showing a gap between the recording headmoved upward from the state in FIG. 28( a) and the platen.

FIG. 29 is a front view of the position of non-action of a wiping memberequipped in the recording apparatus in FIG. 27.

FIG. 30 is a developed view of essential portions on the circumferentialsurface of a cylindrical cam in FIG. 29.

FIG. 31 is a front view of the first position of action of the wipingmember in FIG. 29.

FIG. 32 is a front view of the second position of action of the wipingmember in FIG. 29.

FIG. 33 is a developed view of the side of a cylindrical cam accordingto a sixth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first embodiment embodying the present invention will be describedbelow with reference to FIGS. 1 to 6.

As shown in FIG. 1, an ink jet type recording apparatus 11 as a liquidejection apparatus has a frame 12, a platen 13 hung across the frame 12and an unillustrated paper feeding mechanism equipped with a feed motor14. The platen 13 is a support to support paper P and the paper P fed bythe driving of the feed motor 14 is led to the top surface. The feedmotor 14 drives unillustrated rollers to feed the paper P supported onthe platen 13 in the direction of the arrow y shown in FIG. 1. A wasteliquid tank 40 which retains used inks is provided under the platen 13.

A drive pulley 19 and a driven pulley 20 are fixed to the frame 12. Areversible carriage motor 18 is coupled to the drive pulley 19. A timingbelt 17 is stretched around a pair of the pulleys 19 and 20. A carriage16 is fixed to the timing belt 17. Further, a guide member 15 extendingin parallel to the platen 13 is provided on the frame 12. The guidemember 15 extends in parallel to the axial line extending in thelengthwise direction of the platen 13. The carriage 16 is supported onthe guide member 15 in such a way as to be movable along the axialdirection of the guide member 15. The carriage 16 reciprocates along theguide member 15 via the timing belt 17 by the driving of the carriagemotor 18.

First and second ink cartridges 21 and 22 are detachably mounted on thecarriage 16. The first ink cartridge 21 retains a black ink. The secondink cartridge 22 respectively retains magenta, cyan and yellow inks inthree defined retaining chambers. A recording head 28 as a liquidejection head is provided under the carriage 16. The recording head 28has a plurality of unillustrated nozzles. A discharge port is providedin the bottom side of the nozzle. When an unillustrated piezoelectricelement is driven based on print data, inks are supplied to therecording head 28 from both ink cartridges 21 and 22 and ink dropletsare ejected toward the paper P from the discharge ports to performprinting.

A nozzle protecting device 30 for protecting the nozzles of therecording head 28 is provided at one side portion of the frame 12 whichis the unprintable region (home position). The nozzle protecting device30 also functions as a cleaning apparatus to clean the nozzles.

As shown in FIGS. 2 and 3, the nozzle protecting device 30 has a case31, a cap apparatus 32, a wiping apparatus 34, a cylindrical cam 35, atube pump 37 and a drive motor 38.

The case 31 is a box with a shape approximately corresponding to arectangular parallelepiped. The case 31 has a first retaining portion 41which is open to the top and one side of the case 31 and a secondretaining portion 42 which is open to the top of the case 31. Bothretaining portions 41 and 42 are arranged so as to adjoin each other. Asshown in FIG. 3, a third retaining portion 43 is provided in the case 31in such a way as to adjoin the retaining portions 41 and 42. The thirdretaining portion 43 is closed by a lid 44. An opening 45 is provided atthe boundary between the third retaining portion 43 and the firstretaining portion 41 and the second retaining portion 42.

The cap apparatus 32 is retained in the first retaining portion 41. Thecap apparatus 32 has a box-shaped cap 46 and a cap support member 47 tobe coupled to the cap 46. The cap support member 47 has first to fourthsides 471, 472, 473 and 474. The cap support member 47 is supported atthe first retaining portion 41 in such a way as to be movable along theup and down direction of the first retaining portion 41.

The cap 46 has an opening. The opening of the cap 46 has such a size asto be able to cover the nozzles of the recording head 28. Aclose-contact portion 51 is provided at the periphery of the opening ofthe cap 46. The close-contact portion 51 tightly connects the cap 46 tothe recording head 28 when the cap 46 covers the nozzles of therecording head 28.

An absorption member 52, which is a sheet, is provided inside the cap46. The absorption member 52 functions in such a way that when the cap46 covers the nozzles of the recording head 28, the absorption member 52retains the inks to keep the humidity inside the cap 46 high and preventthe ink from becoming dry. To prevent clogging of inks in the dischargeports at which there is not much discharge of ink droplets, theabsorption member 52 receives inks dropping from the discharge ports atthe time of a flashing operation of applying a drive signal irrelevantto printing to the recording head 28 whenever a given period elapses andejects ink droplets.

Two exhaust ports 53 penetrating the bottom of the cap 46 are formed inthe cap bottom. As shown in FIG. 4, each exhaust port 53 is connected toan associated ink tube 53 a. The ink remaining in the cap 46 isexhausted via each ink tube 53 a. Further, highly viscous ink, dust,bubbles or the like is sucked out of the nozzles via each ink tube 53 ato clean the nozzles.

A vent hole 54 as a through hole is formed in the bottom of the cap 46.The vent hole 54 functions to allow a flow of air into the cap 46. In astate where the ink remaining in the cap 46 is exhausted, i.e., at thetime of air suction to evacuate the inside of the cap 46, air is ledthrough the vent hole 54.

As shown in FIG. 5, a cylinder portion 55 extends from the bottom of thecap 46. The cylinder portion 55 surrounds the vent hole 54. A valve seat56 which surrounds the distal end of the vent hole 54 is provided at thelower end of the cylinder portion 55. The valve seat 56 is formed of aflexible material, for example, an elastomer.

As shown in FIGS. 4 and 5, two bearings 57 are arranged at the lowerportion of the cap 46 in such a way as to face each other. A valve body58 is attached to both bearings 57 in such a way as to be rotatablearound a shaft 62 a. The valve body 58 further includes a plate 61extending in the lengthwise direction of the cap 46 and a supportportion 62 provided near the center of the plate 61. The shaft 62 a isprovided at the upper end of the support portion 62.

A first portion of the plate 61 (the left-hand portion of the plate 61in FIG. 5) is coupled to the lower side of the cap 46 via a springmember 58 a as an urging means. The spring member 58 a normally urgesthe plate 61 of the valve body 58 downward. In the case where noexternal force is applied to the valve body 58, the top surface of asecond portion of the plate 61 (the right-hand portion of the plate 61in FIG. 5) abuts on the valve seat 56, so that the vent hole 54 issealed. A first inclined surface 61 a inclined at a predetermined angleto the direction vertical to the cap support member 47 is formed at theend portion of the second portion of the plate 61.

A first column portion 63 is protrusively provided at the third side 473of the cap 46 and a second column portion 64 is protrusively provided atthe second side 472 of the cap 46.

The cap support member 47 is an approximately rectangular frame and thecap 46 is housed inside the cap support member 47. As shown in FIG. 5, afirst long groove 65 extending along the vertical direction in FIG. 5 isformed in the third side 473 of the cap support member 47. As shown inFIGS. 4 and 5, a second long groove 66 extending along the verticaldirection in the drawing is formed in the side of the cap support member47. The column portions 63 and 64 of the cap 46 penetrate the associatedlong grooves 65 and 66 and are movable in the long grooves 65 and 66along the vertical direction. The upper end of each associated longgroove 65, 66 is cut away in such a way as to have a triangular crosssection.

As shown in FIG. 4, a restriction plate 67 a is provided at that portionof the cap support member 47 which is positioned nearly in the center inthe widthwise direction thereof. The restriction plate 67 a and thefirst side 471 of the cap support member 47 define an opening 67. Theopening 67 is provided at a position facing the tube pump 37. A firstshort groove 68 having an approximately U-shaped cross section is formedin the second side 472 of the cap support member 47. The first shortgroove 68 extends from the lower portion of the second side 472 of thecap support member 47 toward the upper portion. A second short groove 69having an approximately U-shaped cross section is formed in therestriction plate 67 a. The second short groove 69 extends from thelower portion of the restriction plate 67 a toward the upper portion.

As shown in FIGS. 4 and 5, a slide member 71 as a pressing member isprovided at the opening 67. The slide member 71 includes a columnarsupport rod 72, a nearly columnar lever 73 and a link member 74. Thesupport rod 72 and lever 73 are fixed via the link member 74. Both endportions of the support rod 72 are inserted into both short grooves 68and 69 of the cap support member 47. With those structures, the slidemember 71 is movable along the lengthwise direction of the cap supportmember 47 and the movement of the slide member 71 in the direction ofthe arrow y shown in FIG. 4 and the up and down direction of the capsupport member 47 is restricted.

A second inclined surface 73 a inclined relative to the verticaldirection of the cap support member 47 is formed at a first end portionof the lever 73 (equivalent to the left-hand portion of the lever 73 inFIG. 5). Meanwhile, a second end portion of the lever 73 (equivalent tothe right-hand portion of the lever 73 in FIG. 5) is inserted in a thirdlong groove 75 formed in the second side 472 of the cap support member47.

The link member 74 is not movable in the vertical direction of the capsupport member 47. The link member 74 has a plate-like restrictionportion 76 extending in a direction orthogonal to the axis of thesupport rod 72. As the slide member 71 moves toward the widthwise centerof the cap support member 47, the restriction portion 76 abuts on therestriction plate 67 a of the cap support member 47. As a result, themovement of the slide member 71 along the widthwise direction of the capsupport member 47 is restricted.

As shown in FIG. 4, the restriction portion 76 is provided with aprojection 76 a protruding in the direction of the arrow x in FIG. 4. Asshown in FIG. 5, a spring member 77 as an urging means is providedbetween the projection 76 a and the inner surface of the second side 472of the cap support member 47. The spring member 77 urges the slidemember 71 leftward or toward the widthwise center of the cap supportmember 47. In the case where external force is not applied to the slidemember 71, the restriction portion 76 of the slide member 71 and therestriction plate 67 a of the cap support member 47 abut on each other.

As shown in FIG. 4, a through hole 78 is formed in that portion of thefirst side 471 of the cap support member 47 which faces the drive motor38. A columnar positioning member 79 is inserted in the through hole 78.The positioning member 79 is movable along the direction of the arrow yshown in FIG. 4. The positioning member 79 is connected to the capsupport member 47 via an unillustrated spring member. The spring memberurges the positioning member 79 in the direction of the arrow y shown inFIG. 4.

The cap 46 is coupled to the cap support member 47 via a spring member80 as an elastic means as shown in FIG. 5 in such a way that both columnportions 63 and 64 of the cap 46 penetrate to the respective longgrooves 65 and 66 of the cap support member 47. The spring member 80urges the cap 46 in such a way that the cap 46 and the cap supportmember 47 are separated from each other along the vertical direction ofthe cap support member 47. The movements of the cap 46 in the directionof the arrow x and the direction of the arrow y shown in FIG. 4 withrespect to the cap support member 47 are restricted.

With no external force applied to the cap 46, therefore, the distancebetween the cap 46 and the cap support member 47 in the verticaldirection reaches a maximum. As shown in FIG. 5, the individual columnportions 63 and 64 of the cap 46 abut on the upper end portions of therespective long grooves 65 and 66 of the cap support member 47, thusrestricting an increase in the distance between the cap 46 and the capsupport member 47.

With the cap 46 and the cap support member 47 coupled together, theinclined surface 61 a of the valve body 58 (plate 61) of the cap 46 andthe inclined surface 73 a of the lever 73 are placed at positions facingeach other with a predetermined distance therebetween. As will bediscussed later, when the distance between the cap 46 and the capsupport member 47 is at a minimum, the lever 73 is positioned above theplate 61. When the distance between the cap 46 and the cap supportmember 47 is at the maximum, the lever 73 is positioned below the plate61 and outside the movable range of the plate 61.

As shown in FIGS. 1 to 3, the wiping apparatus 34 is housed in thesecond retaining portion 42 of the case 31 in such a way as to bemovable in the vertical direction of the case 31. The wiping apparatus34 has a wiping member 81 which has an approximately rectangularparallelepiped shape and is formed of an elastic material. Therefore,when the carriage 16 is driven with the wiping apparatus 34 moved to theupper portion and the recording head 28 crosses above the wipingapparatus 34, the wiping member 81 slides in contact with the recordinghead 28 to wipe the nozzles of the recording head 28 clean.

As shown in FIG. 6, the cylindrical cam 35 has an insertion hole 82inside. An upper end portion 83 and a lower end portion 84 of thecylindrical cam 35 are both annular and extend in the diametricaldirection of the cylindrical cam 35. A plurality of teeth 85 having thesame shape are formed at an equal pitch on only one circumferential halfof the periphery of the upper end portion 83 of the cylindrical cam 35.The remaining circumferential half of the upper end portion 83 of thecylindrical cam 35 has a smooth arcuate shape. A cam groove 86 isprovided between the upper end portion 83 and the lower end portion 84of the cylindrical cam 35. The cam groove 86 is provided below thatportion of the upper end portion 83 which has a smooth shape and isdefined by fourteen, first to fourteenth surfaces 87 to 100.

The cylindrical cam 35 is positioned in the opening 45 of the thirdretaining portion 43 as shown in FIG. 3. A shaft portion 102 fixed tothe third retaining portion 43 is inserted into the insertion hole 82 ofthe cylindrical cam 35. The cylindrical cam 35 rotates about the shaftportion 102. With the cylindrical cam 35 inserted in the shaft portion102, the positioning member 79 (see FIG. 4) of the cap support member 47is engaged with the cam groove 86 of the cylindrical cam 35.

As the cylindrical cam 35 is rotated in the direction of the arrow, asshown in FIG. 6, first, the positioning member 79 placed at the lowestposition of the cam groove 86 (the position for contact with the lowerend portion 84) is guided to the highest position by the first to thirdsurfaces 87, 88 and 89 extending askew to the axial direction of thecylindrical cam 35. As the cylindrical cam 35 is further rotated in thearrow direction, the positioning member 79 abuts on the sixth to eighthsurfaces 92, 93 and 94 via the fourth and fifth surfaces 90 and 91extending in parallel to the axial direction. The distances from therotational center of the cylindrical cam 35 to the three surfaces 90, 91and 92 become gradually longer. The positioning member 79 is pressed inthe direction opposite to the direction of the arrow y (see FIG. 4).

As the cylindrical cam 35 is rotated in the direction opposite to thearrow in FIG. 6 thereafter, the positioning member 79 is guided to thesixth surface 92 and then abuts on the ninth surface 95 farther from therotational center of the cylindrical cam 35 than the fourth surface 90.Then, it is guided to the seventh surface 93 extending askew to therotational direction and the cap support member 47 as a whole slidesdownward due to the dead weight. Thereafter, it abuts on the twelfth andthirteenth surfaces 98 and 99 through the tapered tenth and eleventhsurfaces 96 and 97. The distances of the three surfaces 95, 96 and 97from the rotational center gradually become longer and the positioningmember 79 is pressed further in the direction opposite to the directionof the arrow y (see FIG. 4).

When the cylindrical cam 35 is rotated again in the direction of thearrow in FIG. 6, the positioning member 79 is guided to the twelfth andthirteenth surfaces 98 and 99, positioned in parallel to the rotationaldirection, and abuts on the fourteenth surface 100. When the cylindricalcam 35 is rotated in the direction opposite to the direction of thearrow thereafter, the positioning member 79 is guided to the twelfth andthirteenth surfaces 98 and 99 and then guided to the first and secondsurfaces 87 and 88, and the cap support member 47 slides downward and isreturned to the initial, lowest position due to the dead weight. Thesecond surface 88 has a shorter distance from the rotational center thanthe twelfth surface 98 and the positioning member 79 is returned in thedirection of the arrow y (see FIG. 4) by the action of the springmember. The positioning member 79 is guided in the up and down directionby the rotation of the cylindrical cam 35 as described above.Accordingly, the cap support member 47 as a whole is moved in the up anddown direction.

As shown in FIG. 3, the tube pump 37 is retained in the third retainingportion 43 of the case 31 in such a way as to not contact thecylindrical cam 35. As shown in FIG. 4, the tube pump 37 has a pumpwheel 105, rotatably supported on a rotary shaft 104, and a roller 106which moves along an unillustrated support groove of the pump wheel 105.The ink tubes 53 a are positioned, partly overlapped, in the spacebetween the third retaining portion 43 (see FIG. 3) and the pump wheel105. In FIG. 4, the ink tube 53 a is illustrated only partially for thesake of convenience.

As the pump wheel 105 is rotated in the forward direction, the roller106 rotates while sequentially pressing the ink tubes 53 a. Thisdepressurizes the inside of the ink tubes 53 a on the upstream side ofthe tube pump 37.

As the pump wheel 105 is rotated in the reverse direction, a releasestate where the roller 106 slightly contacts the ink tubes 53 a ismaintained. As a result, the pressure in the tube pump 37 becomesuniform over the entire tube pump 37. Further, a shortcoming caused byadhesion or the like of the roller 106 and the ink tubes 53 a isprevented.

As shown in FIG. 3, the drive motor 38 is housed in the third retainingportion 43 in such a way as to be rotatable forward and reversely. Theforward/reverse rotation causes the drive force of the drive motor 38 tobe transmitted to the wiping apparatus 34, the cylindrical cam 35 andthe tube pump 37 via first to fourth gears 107 to 110.

A drive gear 38 a is fixed to the distal end of the rotary shaft of thedrive motor 38. The drive gear 38 a is coupled to the third gear 109 viathe first gear 107 and the second gear 108 which are rotatably supportedon the case 31. The third gear 109 is fixed to the distal end of therotary shaft 104 of the tube pump 37 retained in a retaining portion Kcof the case 31. The third gear 109 is further coupled to the fourth gear110 rotatably supported on the case 31. Plural teeth of the fourth gear110 are engaged with the teeth 85 of the cylindrical cam 35 shown inFIG. 6.

As the drive motor 38 is rotated forward, the drive force of the drivemotor 38 is transmitted to the cylindrical cam 35 via the first tofourth gears 107, 108, 109 and 110 and the cylindrical cam rotates inthe direction of the arrow as shown in FIG. 6. Because the plural teeth85 are provided only on one circumferential half of the cylindrical cam35, they only rotate the cam by one-half of its circumference atmaximum. When the forward rotation of the drive motor 38 is changed tothe reverse rotation, the cylindrical cam 35 is rotated in the directionopposite to the direction of the arrow. The cylindrical cam 35 onlyrotates by one-half of its circumference at maximum this time again.

As shown in FIG. 4, the third gear 109 is so arranged as to overlap theupper side of the pump wheel 105 of the tube pump 37 and is rotatablysupported on the rotary shaft 104. A first projection 110 a projectsfrom the lower surface of the third gear 109. Meanwhile, a secondprojection 105 a is provided at the top surface of the pump wheel 105and the first projection 110 a and the second projection 105 a are equalin distance from the rotary shaft 104. The first projection 110 a andthe second projection 105 a are provided in such a way as to partlyoverlap each other in the rotational direction of the rotary shaft 104.In accordance with the relative positions of the fourth gear 110 and thepump wheel 105 in the rotational direction, the first projection 110 aand the second projection 105 a selectively abut on each other or moveapart from each other.

When the forward rotation of the drive motor 38 rotates the third gear109 in the forward direction so that the first projection 110 a and thesecond projection 105 a abut on each other, therefore, the torque of thethird gear 109 is transmitted via the projections 105 a and 110 a to thepump wheel 105 so that the pump wheel 105 rotates forward.

When the forward rotation of the drive motor 38 is changed to thereverse rotation, the third gear 109 changes its forward rotation to thereverse direction, causing the first projection 110 a and the secondprojection 105 a to part from each other. Then, the rotation of the pumpwheel 105 stops. When the third gear 109 makes nearly one turnthereafter, the first projection 110 a and the second projection 105 aabut on each other again to transmit the torque of the third gear 109via the projections 105 a and 110 a to the pump wheel 105, so that thepump wheel 105 rotates reversely.

That is, there is a time lag of nearly one turn of the third gear 109set between the switching of the forward rotation of the drive motor 38to the reverse rotation and the start of the reverse rotation of thepump wheel 105. Likewise, there is a similar time lag set between theswitching of the reverse rotation of the drive motor 38 to the forwardrotation and the start of the forward rotation of the pump wheel 105.

In the case where the drive motor 38 rotates reversely and then startsrotating forward, therefore, first, the cylindrical cam 35 makes half arotation at maximum in the direction of the arrow in FIG. 6. As thedrive motor 38 further rotates forward, the pump wheel 105 startsrotating forward with a delay. In the case where the drive motor 38rotates forward and then starts rotating reversely, the cylindrical cam35 makes half a turn at maximum in the direction opposite to thedirection of the arrow in FIG. 6. As the drive motor 38 further rotatesreversely, the pump wheel 105 starts rotating reversely with a delay.

The action of the nozzle protecting device 30 with the above-describedstructure will be described based on FIGS. 7 to 11. In FIGS. 7 to 11,the illustration of the cap support member 47 is limited only to theslide member 71 and the positioning member 79 for the sake ofconvenience. Further, the illustration of the individual spring members58 a, 77 and 80 is omitted for the sake of convenience.

First, a process of executing a cleaning operation and flashingoperation is executed in the recording apparatus 11, in which thecarriage 16 is moved to the home position of the frame 12. Then, asshown in FIG. 7, the recording head 28 of the carriage 16 faces the cap46 of the nozzle protecting device 30. In this state, the positioningmember 79 is engaged with the cam groove 86 of the cylindrical cam 35shown in FIG. 6 at the lowest position; specifically, it abuts on thefirst surface 87 and the second surface 88 of the cam groove 86.

FIG. 7 shows a state where the distance between the cap 46 and thepositioning member 79 (cap support member 47) is maximum. The lever 73included in the slide member 71 is arranged below the valve body 58 ofthe cap 46. The plate 61 of the valve body 58 abuts on the valve seat 56so that the vent hole 54 is closed. In this state, even when theflashing operation is performed and the inks inside the cap 46 aredischarged, the inks are prevented from leaking from the vent hole 54.

After the cleaning operation is carried out, the drive motor 38 isrotated forward and the drive force of the drive motor 38 is transmittedto the teeth 85 of the upper end portion 83 of the cylindrical cam 35via all of the gears 107, 108, 109 and 110 (see FIG. 3), causing thecylindrical cam 35 to rotate in the direction of the arrow in FIG. 6.Then, the positioning member 79 moves and rises while abutting on thesecond and third surfaces 88 and 89 of the cam groove 86 of thecylindrical cam 35.

Then, the cap support member 47 rises in accordance with the rising ofthe positioning member 79, the close-contact portion 51 of the cap 46abuts on the recording head 28 and covers the recording head 28 as shownin FIG. 8. The upward movement of the cap 46 is restricted by therecording head 28. Further, the spring member 80 provided between thecap 46 and the cap support member 47 elastically deforms, thus reducingthe relative distance between the cap 46 and the cap support member 47.

Consequently, as a predetermined time elapses, the inclined surface 61 aof the plate 61 abuts on the inclined surface 73 a of the lever 73.Further, as the drive motor 38 is rotated forward to move the capsupport member 47 upward, the resistance between the inclined surface 73a of the plate 61 and the inclined surface 61 a of the lever 73 prevailsagainst the elastic force of the spring member 77, so that the springmember 77 elastically deforms, causing the lever 73 to move rightward asshown in FIG. 9.

As the positioning member 79 moves to the position in the cam groove 86of the cylindrical cam 35 shown in FIG. 6 where the third surface 89 andthe fourth surface 90 abut on each other, the distance between the cap46 and the cap support member 47 reaches the minimum and the lever 73 ispositioned above the plate 61 of the lever 73, as shown in FIG. 10. Atthis time, the lever 73 is moved leftward due to elastic restoration ofthe spring member 77 of the slide member 71.

As the drive motor 38 is rotated further forward, the positioning member79 slides in abutment on the fifth to seventh surfaces 91, 92 and 93 ofthe cam groove 86 of the cylindrical cam 35 shown in FIG. 6 and abuts onthe eighth surface 94. Then, the teeth 85 of the upper end portion 83 ofthe cylindrical cam 35 moves to the position where it does not contactthe third gear 109 (see FIG. 3) and the rotation of the cylindrical cam35 is stopped.

When the rotation of the cylindrical cam 35 is stopped and the drivemotor 38 continues rotating further forward, the pump wheel 105 of thetube pump 37 starts the forward rotation. As shown in FIG. 10,therefore, the nozzles of the recording head 28 are covered with the cap46 and with the valve seat 56 abutting on the plate 61, the suction bythe tube pump 37 is carried out. Then, the inside of the cap 46 isdepressurized.

Then, inks as fluids in the ink cartridges 21 and 22 (see FIG. 1), flowinside the cap 46 via the nozzles of the recording head 28. Inks withincreased viscosity in the vicinity of the nozzles, dust adhered to thenozzles, bubbles generated by replacement of the cartridges, or the likeare exhausted to the outside via the ink tubes 53 a and the cleaningoperation is executed.

Thereafter, when the driving of the drive motor 38 is stopped andsuction by the tube pump 37 is stopped, the inks are held inside the cap46.

In the case where printing starts again from the state shown in FIG. 10,the drive motor 38 is rotated reversely. Then, the drive force of thedrive motor 38 is transmitted to the teeth 85 of the cylindrical cam 35shown in FIG. 6 via the first to third gears 107 to 109 (see FIG. 3) andthe cylindrical cam 35 is rotated in the direction opposite to thedirection of the arrow in FIG. 6.

Then, the positioning member 79 moves in abutment on the seventh surface93, the ninth surface 95, the tenth surface 96 and the eleventh surface97 of the cylindrical cam 35 and moves downward to the position where itabuts on the twelfth and thirteenth surfaces 98 and 99. Therefore, thecap support member 47 moves downward and the spring member 80 providedbetween the cap support member 47 and the cap 46 is elasticallyrestored. As a result, as shown in FIG. 11, with the cap 46 abutting onthe recording head 28, the lever 73 of the cap support member 47 movesdownward so that downward pressure is applied to the plate 61 of the cap46 from the lever 73. Consequently, the plate 61 is rotated clockwise inFIG. 11 about the shaft 62 a as the rotational center and the valve seat56 is separated from the plate 61.

Because the drive force of the drive motor 38 is not transmitted to thetube pump 37 at this time, the tube pump 37 is stopped with the roller106 pressing against the ink tubes 53 a. Even if the valve seat 56 andthe plate 61 are separated from each other to set the vent hole 54 open,therefore, the ink tubes 53 a are pressed so that inks do not leakthrough the vent hole 54.

The drive motor 38 is rotated forward again, the drive force of thedrive motor 38 is transmitted to the teeth 85 of the cylindrical cam 35via the first to third gears 107 to 109 and the cylindrical cam 35 isrotated in the direction of the arrow in FIG. 6. Then, the positioningmember 79 slides in abutment on the twelfth and thirteenth surfaces 98and 99 of the cylindrical cam 35 and abuts on the fourteenth surface100. Then, the teeth 85 of the cylindrical cam 35 moves to the positionwhere it does not contact the third gear 109 (see FIG. 3) and therotation of the cylindrical cam 35 is stopped.

When the rotation of the cylindrical cam 35 is stopped, the rotation ofthe tube pump 37 is started. As shown in FIG. 11, therefore, the nozzlesof the recording head 28 are covered with the cap 46 and with the valveseat 56 set apart from the plate 61, the suction by the tube pump 37 iscarried out. As a result, the inside the cap 46 is depressurized.

Then, air flows inside the cap 46 via the vent hole 54. Then, the inksheld inside the cap 46 are exhausted to the outside via the ink tubes 53a and so-called air suction is carried out. Consequently, the of theinside the cap 46 is filled with air.

When the driving of the drive motor 38 is stopped, suction by the tubepump 37 is stopped and then the drive motor 38 is rotated reversely, thedrive force of the drive motor 38 is transmitted to the teeth 85 of thecylindrical cam 35 shown in FIG. 6 via the first to third gears 107 to109, and the cylindrical cam 35 is rotated in the direction opposite tothe arrow direction.

The positioning member 79 slides in abutment on the twelfth andthirteenth surfaces 98 and 99 and moves downward in abutment on thefirst and second surfaces 87 and 88. Then, the cap support member 47moves downward and the lever 73 moves downward outside the movable rangeof the plate 61. As a result, the plate 61 rotates counterclockwise inFIG. 11 about the shaft 62 a due to elastic restoration of the springmember 58 a and abuts on the valve seat 56.

When the positioning member 79 moves down to the position where itcontacts the lower end portion 84 of the cylindrical cam 35 shown inFIG. 6, the distance between the cap 46 and the cap support member 47reaches maximum and the cap 46 parts from the recording head 28 as shownin FIG. 7.

At this time, the inks are not held inside the cap 46 because of airsuction being performed, so that even if the recording apparatus 11 isplaced in a state other than a horizontal state, the inks do not fallfrom the cap 46.

The present embodiment has the following advantages.

With the driving of the drive motor 38, the nozzles are covered with thecap 46, making it possible to prevent the inks in the nozzles frombecoming dried. Further, it is possible to change the distance betweenthe cap 46 and the cap support member 47 by driving the drive motor 38and selectively opening and closing the inside the cap 46 with respectto air. It is therefore possible to control both prevention of the inksin the nozzles from becoming dried and opening and closing of the insideof the cap 46 with respect to air by using the single drive motor 38. Asa result, the apparatus can be simplified.

With the cap 46 covering the nozzles, air suction can be performed byseparating the plate 61 from the valve seat 56, opening the inside ofthe cap 46 to air and driving the tube pump 37. With this structure,even if the recording apparatus 11 is placed in a state other than ahorizontal state, it is possible to make it difficult for the inksinside the cap 46 to leak to the outside.

The valve seat 56 is formed of a flexible material. Therefore, the plate61 tightly contacts the valve seat 56 well, so that with the plate 61abutting on the valve seat 56, it is possible to prevent the inks fromleaking or air from flowing in from the abutting portion. This canmaintain the performance of the apparatus adequately.

When the distance between the cap support member 47 and the cap 46 isminimum (see FIG. 10), the lever 73 is placed above the valve body 58(plate 61). When the distance between the cap support member 47 and thecap 46 increases, the lever 73 contacts the plate 61 from above andpresses the plate 61 downward. If the drive motor 38 is driven in thedirection of reverse rotation with the cap 46 covering the nozzles,therefore, the distance between the cap support member 47 and the cap 46increases, so that the plate 61 is pressed downward from above and partsfrom the valve seat 56, setting inside the cap 46 open to air. It ispossible to execute air suction by driving the tube pump 37 by drivingthe drive motor 38 in the forward rotation.

When the drive motor 38 is further driven in the direction of reverserotation, the distance between the cap support member 47 and the cap 46reaches maximum, making it possible to separate the cap 46 from therecording head 28. That is, the inside of the cap 46 can be opened toair at the suitable timing for air suction, which is immediately beforeseparation of the cap 46 from the recording head 28.

The spring member 58 a urges the plate 61 in a direction to abut on thevalve seat 56. When downward force is applied to the plate 61 fromabove, therefore, the plate 61 is set apart from the valve seat 56,opening the inside of the cap 46 to air, but the vent hole 54 is closedby the urging force of the spring member 58 a otherwise. That is, onlywhen air suction is performed, downward force is applied to the plate 61from above to set the inside of the cap 46 open to air, and the plate 61can be made to abut on the valve seat 56 otherwise. At times than otherduring the air suction, therefore, the vent hole 54 can be closed byabutting the plate 61 on the valve seat 56, thereby making it possibleto prevent the inks from leaking to the outside as a result of the venthole 54 being opened.

The plate 61 is rotatable with respect to the cap 46 and the lever 73 isplaced outside the movable range of the plate 61 when the distancebetween the cap support member 47 and the cap 46 is maximum. Even if theplate 61 is separated from the valve seat 56 pressed downward by thelever 73, when the distance between the cap 46 and the cap supportmember 47 reaches maximum, the lever 73 is placed outside the movablerange of the plate 61, so that the plate 61 is not pressed by the lever73. As a result, the plate 61 moves upward due to the urging force ofthe spring member 58 a and abuts on the valve seat 56. When the distancebetween the cap 46 and the cap support member 47 reaches maximum, i.e.,when the cap 46 is separated from the nozzles of the recording head 28,therefore, the vent hole 54 is closed. For example, leakage of the inksfrom the vent hole 54 can be prevented at the time of performing theflashing (reserve ejection) operation to prevent clogging or the like ofthe openings of the nozzles by discharging the inks by application of adrive signal irrelevant to printing by the recording head 28.

The inclined surfaces 61 a and 73 a inclined in the movement directionof the cap support member 47 are respectively formed on the lowersurface of the plate 61 and the top surface of the lever 73. When thelever 73 pushes the plate 61 in such a direction that the plate 61 abutson the valve seat 56, therefore, the pressing force of the lever 73 isconverted to a force to slide the lever 73 itself. It is thereforeunnecessary to separately provide a drive mechanism to slide the lever73, making it possible to simplify the structure of the apparatus.

The lever 73 is provided with the urging member to urge the lever 73itself in the slide direction. Even if the lever 73 is slid to avoid theplate 61 when the lever 73 is moved upward, it is returned to theoriginal position by the urging member. This can simplify the drivemechanism for sliding the lever 73 and can simplify the structure of theapparatus.

The drive force of the drive motor 38 is transmitted to the cap supportmember 47 via the cylindrical cam 35 to move the cap support member 47up and down. Based on the shape of the cylindrical cam 35, therefore,the up/down position of the cap support member 47 can be finely changed.And, it is possible to easily execute control to selectively open andclose the inside of the cap 46 with respect to air while covering thenozzles with the cap 46 or to separate the cap 46 from the nozzles.

The drive force from the drive motor 38 is transmitted to thecylindrical cam 35, which moves the cap support member 47 up and down,and the tube pump 37 with a predetermined phase difference. Therefore,the up and down movement of the cap support member 47 and the driving ofthe tube pump 37 can be accomplished by a single drive motor 38. Thisresults in elimination of the need to provide a plurality of drivemotors 38 in order to prevent the inks in the nozzles from becomingdried and executing air suction, thus making it possible to simplify thestructure of the apparatus.

A second embodiment embodying the present invention will be describedbelow with reference to FIGS. 12 to 15. As compared with the embodimentin FIGS. 1 to 11, members including the valve body 58, the support rod72 and the lever 73 are omitted and an air release means different fromthat of the embodiment in FIGS. 1 to 11 is provided in this embodiment.In this embodiment, those items which differ from the embodiment inFIGS. 1 to 11 are described and the same symbols are given to similarportions and their descriptions are omitted. FIGS. 12 to 15 are sideviews of the cap apparatus 32 according to this embodiment as seen fromthe third retaining portion 43 (see FIG. 3).

The cap apparatus 32 has a cap 120 and a cap support member 121 coupledto the cap 120, as shown in FIG. 12. The cap support member 121 issupported at the first retaining portion 41 in FIG. 3 in such a way asto be slidable in the up and down direction.

The cap 120, like the cap 46 in FIG. 2, is a box with the top side open,and is retained inside the cap support member 121 which is formed in anapproximately rectangular frame. The opening of the cap 120 has such asize as to be able to cover the nozzles of the recording head 28. Theclose-contact portion 51 is provided at the periphery of the opening ofthe cap 120.

The exhaust ports 53 provided in the bottom of the cap 120 are connectedto the ink tubes 53 a and the inks remaining in the cap 120 areexhausted via the ink tubes 53 a.

The vent hole 54 as a through hole is formed in the bottom of the cap120 (see FIG. 5). The proximal end of an air tube 122 is connected tothe vent hole 54 and the distal end of the air tube 122 is led aroundfrom below the cap 120 and is supported from the inside of the capsupport member 121 to the outer side surface (the third retainingportion 43 side) via a hole portion 121 a. Further, a valve seat 123 isprovided integral with the distal end of the air tube 122. The air tube122 and the valve seat 123 are formed of a flexible material, forexample, an elastomer.

The vent hole 54 permits exhaustion of inks remaining in the cap 120 andpermits flow of air into the cap 120 via the air tube 122 at the time ofair suction to evacuate inside the cap 120. As air is taken into thevent hole 54 via the air tube 122, it is possible to prevent inks fromleaking from the vent hole 54.

As shown in FIG. 12, a shaft 124 is protrusively provided on the outerside surface of the cap support member 121. A valve body 126 isrotatably attached to the shaft 124. A first spring member 125 which is,for example, a torsion coil spring, is attached to the valve body 126.The valve body 126 includes an annular-shaped support portion 127 and anextension plate 128 extending from the support portion 127. A projection129 is formed at the periphery of the support portion 127 at a positionopposite to the extension plate 128.

As the valve body 126 rotates counterclockwise in FIG. 12, a side 128 aof the extension plate 128 abuts on the valve seat 123 of the air tube122. Accordingly, the vent hole 54 is sealed via the air tube 122. Asthe valve body 126 rotates clockwise in FIG. 12, the side 128 a of theextension plate 128 parts from the valve seat 123 of the air tube 122.Accordingly, air flows into the cap 120 passing through the air tube 122and the vent hole 54.

The valve body 126 is normally urged in the counterclockwise directionby the first spring member 125. In the case where no external force isapplied to the valve body 126, therefore, the side 128 a of theextension plate 128 always abuts on the valve seat 123, sealing the venthole 54. Further, in a case the where leftward force is applied to theprojection 129 from the right side in FIG. 12, the extension plate 128rotates clockwise about the shaft 124 against the elastic force of thefirst spring member 125 and parts from the valve seat 123. As a result,air flows into the cap 120 passing through the air tube 122 and the venthole 54.

The cap 120 is connected to the cap support member 121 via a secondspring member 130. The second spring member 130 urges the cap 120 in adirection to separate the cap 120 and the cap support member 121 fromeach other in the up and down direction.

As shown in FIG. 12, the cap 120 has a stop portion 131 extending upwardof the cap 120. The cap support member 121 has an engage portion 132which is open toward the end portion of the cap support member 121 andhas a trapezoidal cross section. As the stop portion 131 of the cap 120engages with the engage portion 132 of the cap support member 121, anincrease in the distance between the cap 120 and the cap support member121 is restricted.

As shown in FIG. 13, a partition 133 is provided on a bottom 41 a of thefirst retaining portion 41 (see FIG. 3). The partition 133 is arrangedbetween the cap support member 121 and the third retaining portion 43(see FIG. 3).

An abutment portion 134 as a pressing member is formed on the partition133 at a position facing the valve body 126. In accordance with theup/down movement of the cap support member 121, the abutment portion 134selectively abuts on or parts from the projection 129 of the valve body126.

When the projection 129 abuts on the abutment portion 134, theprojection 129 is pressed leftward from the right side in FIG. 12 by theabutment portion 134. Accordingly, the valve body 126 rotates clockwiseabout the shaft 124. As a result, the extension plate 128 of the valvebody 126 is separated from the valve seat 123, releasing the inside ofthe cap 120 to air.

With the cap support member 121 moves to the topmost position as shownin FIG. 14, the abutment portion 134 is placed under the projection 129.In the case where no external force is applied to the cap support member121, with the cap support member 121 moved to the lowermost position asshown in FIG. 13, on the other hand, the abutment portion 134 is placedabove the projection 129.

The action of the nozzle protecting device 30 with the above-describedstructure will be described based on FIGS. 13 to 15.

First, when a process of carrying out a cleaning operation and flashingoperation is executed in the recording apparatus 11, the carriage 16 ismoved to the home position of the frame 12 as in the embodiment in FIGS.1 to 11. Then, as shown in FIG. 13, the recording head 28 of thecarriage 16 faces the cap 120 of the nozzle protecting device 30. Inthis state, the positioning member 79 of the cap support member 121 isengaged with the cam groove 86 of the cylindrical cam 35 shown in FIG. 6at the lowest position; specifically, it abuts on the first surface 87and the second surface 88 of the cam groove 86.

In FIG. 13, the distance between the cap 120 and the cap support member121 is maximum, and the distance between the cap support member 121 andthe partition 133 is minimum. The abutment portion 134 of the partition133 is positioned above the projection 129 of the valve body 126. Theextension plate 128 of the valve body 126 abuts on the valve seat 123 sothat the vent hole 54 is closed via the air tube 122. In this state,even when the flashing operation is performed and the inks are ejectedinside the cap 120, the inks do not leak from the vent hole 54.

In the case where the cleaning operation is performed, on the otherhand, the positioning member 79 of the cap support member 121 movesupward while abutting on the second and third surfaces 88 and 89 of thecam groove 86 (see FIG. 6).

Then, with the upward movement of the positioning member 79, the capsupport member 121 moves upward and the close-contact portion 51 of thecap 120 abuts on the recording head 28, covering the recording head 28.The recording head 28 restricts the upward movement of the cap 120 andelastically deforms the spring member 130 provided between the cap 120and the cap support member 121, thereby decreasing the distance betweenthe cap 120 and the cap support member 121.

At this time, the projection 129 moves upward of the abutment portion134 of the partition 133 in accordance with the upward movement of thecap support member 121. Consequently, when a predetermined time elapses,the projection 129 of the valve body 126 abuts on the abutment portion134 of the partition 133, causing air to flow into the cap 120.Thereafter, the projection 129 moves upward of the abutment portion 134and parts from the abutment portion 134.

Subsequently, the distance between the cap 120 and the cap supportmember 121 reaches a minimum and the projection 129 is positioned abovethe abutment portion 134, as shown in FIG. 14. At this time, theextension plate 128 of the valve body 126 abuts on the valve seat 123due to the elastic restoration of the spring member 125 and the venthole 54 is closed via the air tube 122.

Thereafter, the rotation of the cylindrical cam 35 is stopped and asshown in FIG. 14, the nozzles of the recording head 28 are covered withthe cap 120 and suction by the tube pump 37 is carried out with theextension plate 128 abutting on the valve seat 123. When the inside ofthe cap 120 is depressurized, inks in the ink cartridges 21 and 22 (seeFIG. 1) flow inside the cap 120 via the nozzles of the recording head28. Then, inks with increased viscosity in the vicinity of the nozzles,dust adhered to the nozzles, bubbles generated by replacement of thecartridges, or the like are exhausted to the outside via the ink tubes53 a and the cleaning operation is executed.

Thereafter, when suction by the tube pump 37 is stopped, the inks areretained inside the cap 120.

Subsequently, in the case where printing starts again from the stateshown in FIG. 14, the cap support member 121 is lowered according to theoperation of the cylindrical cam 35 as described in the embodiment inFIGS. 1 to 11. Then, the spring member 130 provided between the capsupport member 121 and the cap 120 is elastically restored.

As a result, as shown in FIG. 15, with the cap 120 abutting on therecording head 28, the projection 129 of the valve body 126 movesdownward and abuts on the abutment portion 134. Leftward force isapplied to the projection 129 from the right side in the diagram by theabutment portion 134. Consequently, the valve body 126 is rotatedclockwise in FIG. 15 about the shaft 124 as the rotational center andthe valve seat 123 is separated from the extension plate 128 and airflows inside the cap 120.

The tube pump 37 is stopped with the roller 106 pressing against the inktubes 53 a as per the embodiment in FIGS. 1 to 11. Even if the extensionplate 128 is separated from the valve seat 123 to set the vent hole 54open via the air tube 122, therefore, the ink tubes 53 a are pressed sothat inks do not leak through the vent hole 54.

Thereafter, as shown in FIG. 15, suction by the tube pump 37 is carriedout with the extension plate 128 separated from the valve seat 123. And,the inside of the cap 120 is depressurized. Then, air flows inside thecap 120 via the air tube 122 and the vent hole 54. Subsequently, theinks held inside the cap 120 are exhausted to the outside via the inktubes 53 a and so-called air suction is performed. As a result, theinside of the cap 120 is filled with air.

Thereafter, after suction by the tube pump 37 is stopped, the capsupport member 121 is lowered according to the operation of thecylindrical cam as per the embodiment in FIGS. 1 to 11. Consequently,the projection 129 moves upward relative to the partition 133 and theextension plate 128 rotates counterclockwise about the shaft 124 in FIG.12 due to the elastic restoration of the spring member 125 and abuts onthe valve seat 123. When the distance between the cap 120 and the capsupport member 121 reaches maximum, the cap 120 is separated from therecording head 28 as shown in FIG. 13. The abutment portion 134 ispositioned above the projection 129 and outside the movable range of theprojection 129 and is separated from the projection 129.

At this time, air suction is performed and the inks are not held insidethe cap 120, so that even if the recording apparatus 11 is set in astate other than a horizontal state, the inks do not leak from insidethe cap 120.

A third embodiment embodying the present invention will be describedbelow with reference to FIGS. 16 to 23. It should be noted that the samesymbols are given to similar portions to those of the recordingapparatus 11 in FIG. 1 and their descriptions are omitted.

As shown in FIG. 16, a cylindrical cam 234 is supported inside aretaining portion Kd of the case 31 by a support portion Ke protrudingat the center thereof. The cylindrical cam 234 is rotatable about therotational axial center C of the support portion Ke. A driven gear 242is provided above the cylindrical cam 234. The driven gear 242 is a spurgear having a plurality of teeth 242 a formed around the entirecircumferential surface at predetermined pitches a. The driven gear 242rotates always in engagement with teeth 110 a of the fourth gear 110. Acompression spring 250 is provided between the driven gear 242 and thelid 44. One end portion of the compression spring 250 is pressed againstthe lid 44 and the other end portion is pressed against the driven gear242, thus pressing the driven gear 242 downward toward the cylindricalcam 234. Therefore, the torque from the driven gear 242 is transmittedto the cylindrical cam 234 by friction.

A partially toothed gear 251 having a ring shape is provided at theupper end portion of the cylindrical cam 234 between the cylindrical cam234 and the driven gear 242. A plurality of teeth 251 a are formed onabout one-half of the circumferential surface of the partially toothedgear 251. The plural teeth 251 a are formed at the same pitches a as thedriven gear 242 and engage with the teeth 110 a of the fourth gear 110.The upper sides of the teeth 110 a of the fourth gear 110 engage withthe teeth 242 a of the driven gear 242 and the lower sides engage withthe teeth 251 a of the partially toothed gear 251 at the same time.

A cam groove 252 is formed in the circumferential surface of thecylindrical cam 234. As shown in FIG. 22, the cam groove 252 includes afirst guide portion 252 a extending along the circumferential directionat the lower portion of the cam groove 252, a second guide portion 252 bextending obliquely upward from the first guide portion 252 a and athird guide portion 252 c extending in parallel along thecircumferential direction from the second guide portion 252 b. As shownin FIG. 20( a) to FIG. 21, a rotation restriction groove 253 having acenter angle of about 200° and an arcuate shape is formed in the bottomof the cylindrical cam 234. The angle defined by lines connecting firstand second end portions 253 a and 253 b of the rotation restrictiongroove 253 to the rotational axial center C of the support portion Ke isgreater than 180 degrees. A stop member 254 is slidably engaged with therotation restriction groove 253. The stop member 254 is fixed to thebottom of the retaining portion Kd of the case 31. When the cylindricalcam 234 rotates, therefore, the stop member 254 abuts on both endportions 253 a and 253 b of the rotation restriction groove 253 (seeFIG. 20( a) to FIG. 21), thus restricting the rotation of thecylindrical cam 234.

Next, the structures of the cylindrical cam 234 and the driven gear 242coaxial to the cylindrical cam 234 are described in detail based onFIGS. 22 and 23. The cylindrical cam 234 includes a first groove-formingmember 255, a second groove-forming member 256 and the partially toothedgear 251. The first groove-forming member 255 and the secondgroove-forming member 256 are equivalent to the rotary member.

The first groove-forming member 255 has a disk-shaped base portion 255a. The rotation restriction groove 253 is formed at the bottom of thebase portion 255 a. A wall portion 255 b extends upward from the top ofthe base portion 255 a. The wall portion 255 b has a cylindrical shapewith a part cut away. A cutaway portion 257 is formed in the wallportion 255 b positioned above the first end portion 253 a of therotation restriction groove 253. The cutaway portion 257 extendsobliquely upward from the top of the base portion 255 a. A first stepportion S2 extending toward the driven gear 242 (see FIG. 20( b)) isformed at the wall portion 255 b positioned above the second end portion253 b of the rotation restriction groove 253.

As shown in FIG. 23, a cylinder portion 255 c apart from the wallportion 255 b by a predetermined distance and concentric thereto isformed at the center of the first groove-forming member 255. A throughhole h is formed in the center of the cylinder portion 255 c and thesupport portion Ke of the case 31 penetrates through the through hole h.

The second groove-forming member 256 has a cylinder portion 256 a. Thecylinder portion 256 a is fitted in the gap between the wall portion 255b of the first groove-forming member 255 and the cylinder portion 255 c.A ring portion 256 b shorter in the axial direction than the cylinderportion 256 a is integrally formed on the circumferential surface ofcylinder portion 256 a. An extension portion 258 is provided at a partof the ring portion 256 b. The axial length of the extension portion 258is shorter than the axial length of the cylinder portion 256 a. Theextension portion 258 has an inclined portion having the sameinclination angle as the inclined portion of the cutaway portion 257.The inclined portion of the extension portion 258 is inserted into thecutaway portion 257 of the first groove-forming member 255. Further, asecond step portion S1 (see FIG. 6( b)) is formed at a part of thecircumferential surface of the ring portion 256 b.

When the cylinder portion 256 a of the second groove-forming member 256is inserted into the gap between the wall portion 255 b of the firstgroove-forming member 255 and the cylinder portion 255 c, therefore, thefirst groove-forming member 255 is disabled to rotate with respect tothe second groove-forming member 256. When the extension portion 258 ofthe second groove-forming member 256 is inserted into the cutawayportion 257 of the first groove-forming member 255, a gap is formedbetween the extension portion 258 and the base portion 255 a. This gapis equivalent to the first guide portion 252 a. A gap is also formedbetween the inclined portion of the cutaway portion 257 and the inclinedportion of the second groove-forming member 256. This gap is equivalentto the second guide portion 252 b. As shown in FIG. 20( b), the stepportion S2 of the first groove-forming member 255 becomes level with thestep portion S1 of the second groove-forming member 256, forming an endwall portion for the third guide portion 252 c. That is, as the firstgroove-forming member 255 is attached to the second groove-formingmember 256, the cam groove 252 is defined and formed. The rotationrestriction groove 253 is formed in an angular range approximately thesame as the angle at which the cam groove 252 is defined and formed.According to this embodiment, therefore, the cylindrical cam 234 isrotatable only in the angular range.

A pair of recess portions 259 are provided at the upper end portion ofthe ring portion 256 b of the second groove-forming member 256. Further,a ring-shaped groove 256 c formed at the upper end of the secondgroove-forming member 256, radially inward of the positions of bothrecess portions 259 and radially outward of the cylinder portion 256 a.

As shown in FIG. 21, the tooth 251 a in the plural teeth 251 a which ispositioned at an end portion E is provided at a position where it nearlyfaces the fourth gear 110 when the stop member 254 abuts on the firstend portion 253 a of the rotation restriction groove 253, i.e., when thecleaning operation is initiated. At the same time as the fourth gear 110rotates in the direction r1, the partially toothed gear 251 engaged withthe fourth gear 110 rotates in the direction r2.

As shown in FIG. 22, a pair of projection portions 260 protrudingdownward are provided on the partially toothed gear 251 at positionsfacing each other. The individual projection portions 260 are engagedwith the respective recess portions 259 of the second groove-formingmember 256. Specifically, when the projection portions 260 are engagedwith the respective recess portions 259, a gap equivalent to a half ofone pitch a of the tooth 251 a is formed between the circumferentialsurface of the projection portion 260 extending in the axial directionand the wall of the recess portion 259 which faces that circumferentialsurface and extends in the axial direction. That is, the partiallytoothed gear 251 can turn by the pitch a of the tooth 251 a with respectto the second groove-forming member 256.

As shown in FIG. 23, a cylinder portion 242 b is formed at the centerportion of the driven gear 242 in such a way as to extend along theaxial direction. The compression spring 250 (see FIG. 16) is fitted overthe upper end portion of the cylinder portion 242 b. The lower endportion of the cylinder portion 242 b is fitted in the ring-shapedgroove 256 c of the second groove-forming member 256. A large-diameterportion 242 c is provided between the driven gear 242 and the cylinderportion 242 b. The large-diameter portion 242 c is fitted in the innerhole of the partially toothed gear 251. Therefore, the driven gear 242is rotatable with respect to the cylindrical cam 234 and rotates aboutthe rotational axial center C of the cylindrical cam 234.

As shown in FIGS. 17 to 19, the nozzle protecting device 30 has a wipingapparatus 235. The wiping apparatus 235 has a wiper support member 261provided along the direction of the arrow y. The wiper support member261 is supported on the case 31 in such a way as to be movable in the upand down direction of the case 31 and to be unmovable in the directionof the arrow y. A holding member 262 is formed extending from the lowerportion of the side of the wiper support member 261 concerning thedirection of the arrow y, as shown in FIGS. 16, 19, 20(a) and 20(b). Asshown in FIGS. 20( a) and 20(b), a positioning member 262 a is formedextending from the distal end of the holding member 262 in the directionof the arrow x. The positioning member 262 a is slidably fitted in thecam groove 252 of the cylindrical cam 234.

As the cylindrical cam 234 is rotated by the drive motor 38, the holdingmember 262 is moved up and down by the positioning member 262 a whichslides in the guide portions 252 a, 252 b and 252 c of the cam groove252. That is, when the positioning member 262 a slides in the firstguide portion 252 a, the positioning member 262 a is guided to aposition of non-action. When the positioning member 262 a slides in thethird guide portion 252 c, the holding member 262 is guided to aposition of action. Further, when the positioning member 262 a slides inthe second guide portion 252 b, the holding member 262 is guided to aposition between the position of non-action and the position of action.

Specifically, as shown in FIGS. 16, 19 and 20(a), when the stop member254 abuts on the first end portion 253 a of the rotation restrictiongroove 253 of the first groove-forming member 255, the fourth gear 110faces the tooth 251 a at the end portion E of the partially toothed gear251 and the positioning member 262 a is positioned at the position whereit abuts on the end wall of the first guide portion 252 a of the camgroove 252. In this state, therefore, the holding member 262 ispositioned at the position of non-action. As the fourth gear 110 isrotated in the direction r1 from this state, the driven gear 242 and thepartially toothed gear 251 rotate in the direction r2. Their rotationcauses the cam groove 252 of the cylindrical cam 234 to rotate and thepositioning member 262 a slides to contact the third guide portion 252 cfrom the first guide portion 252 a of the cam groove 252 through thesecond guide portion 252 b. With the movement of the positioning member262 a, the wiper support member 261 moves upward and reaches theposition of action when the positioning member 262 a slides to contactthe third guide portion 252 c. When the stop member 254 abuts on thefirst end portion 253 b of the rotation restriction groove 253 by therotation of the cylindrical cam 234, as shown in FIG. 20( b), thepositioning member 262 a abuts on the end wall (step portions S1, S2) ofthe third guide portion 252 c of the cam groove 252. As the positioningmember 262 a moves to the third guide portion 252 c from the first guideportion 252 a of the cam groove 252 through the second guide portion 252b, the partially toothed gear 251 engages with the fourth gear 110 butthe partially toothed gear 251 does not engage with the fourth gear 110before the positioning member 262 a reaches the end wall of the thirdguide portion 252 c.

As the drive motor 38 is rotated reversely from the state shown in FIG.20( b) to the state shown in FIG. 20( a), the positioning member 262 aslides to contact the first guide portion 252 a from the third guideportion 252 c through the second guide portion 252 b in the reverseorder to the previously described order. As a result, the wiper supportmember 261 is lowered to the position of non-action from the position ofaction.

A wiping member 263 extending in the direction of the arrow y is fixedto the top of the wiper support member 261. The wiping member 263 isformed of an elastic material, such as rubber. A distal end 263 a of thewiping member 263 is bent in the direction of the arrow x and cleans insuch a way as to wipe off the inks adhered to the recording head 28.That is, when the wiper support member 261 moves upward to the positionof action, the distal end 263 a of the wiping member 263 is pressedagainst the recording head 28, which passes above, from below and wipesoff inks adhered to the recording head 28.

The action of the recording apparatus 11 according to this embodimentwill be described using FIGS. 16 to 20( b) and FIG. 1.

In the case where printing is finished and the cleaning operation of therecording head 28 is to be carried out, the recording apparatus 11drives the carriage motor 18 to move the carriage 16 in the direction ofthe arrow x to the position where the carriage 16 faces the cap 46. Atthis time, the positioning member 262 a of the wiper support member 261is positioned at the first guide portion 252 a of the cam groove 252, asshown in FIGS. 16, 19 and 20(b). Accordingly, even when the carriage 16passes over the wiping member 263 in the direction x, the distal end 263a of the wiping member 263 does not abut on the recording head 28 of thecarriage 16. The tooth 251 a at the end portion E of the partiallytoothed gear 251 faces the fourth gear 110. Further, the stop member 254abuts on the first end portion 253 a of the rotation restriction groove253.

When the carriage 16 arrives at the position facing the cap 46, therecording apparatus 11 stops driving the carriage motor 18 and rotatesthe drive motor 38 forward. When the drive motor 38 is rotated forward,the drive gear 38 a is rotated and its torque is transmitted to thefourth gear 110 via the individual first to third gears 107 to 109. Thefourth gear 110 is rotated in the direction r1 and the driven gear 242which engages with the fourth gear 110 is rotated in the direction r2.When the driven gear 242 starts rotating in the direction r2, the drivengear 242 is pressed downward and the driven gear 242 slides to contactthe partially toothed gear 251, so that the torque of the driven gear242 is transmitted to the partially toothed gear 251 by frictional forceso that the partially toothed gear 251 tries to rotate. Further, as theteeth 251 a of the partially toothed gear 251 are at the position facingthe fourth gear 110, the teeth 251 a of the partially toothed gear 251engage with the fourth gear 110.

As a result, upon reception of the torque from the fourth gear 110, thepartially toothed gear 251 is rotated in the direction r2. As thepartially toothed gear 251 rotates, the partially toothed gear 251rotates with respect to the second groove-forming member 256 until itsprojection portion 260 abuts on the wall of the recess portion 259 inthe direction r2, then rotates together with the first groove-formingmember 255 and the second groove-forming member 256. That is, thecylindrical cam 234 is rotated in the direction r2 and the cam groove252 rotates. Accordingly, the positioning member 262 a of the wipersupport member 261 reaches the third guide portion 252 c through thesecond guide portion 252 b from the first guide portion 252 a of the camgroove 252 where it has been fitted, causing the wiping member 263 tomove upward.

As the positioning member 262 a reaches the third guide portion 252 cand the cylindrical cam 234 makes about a half turn, the teeth 251 a ofthe partially toothed gear 251 do not engage with the fourth gear 110.As the driven gear 242 which slides to contact the partially toothedgear 251 keeps rotating, the torque of the driven gear 242 is convertedto frictional force and is transmitted to the partially toothed gear251, causing the cylindrical cam 234 to further rotate. And, when thestop member 254 abuts on the end portion 253 b of the rotationrestriction groove 253 of the cylindrical cam 234, as shown in FIG. 20(b), the rotation of the cylindrical cam 234 in the direction r2 isstopped.

The cap support member 47 is moved upward by the elevation mechanism,which is driven by torque transmitted from the driven gear 242, and thecap 46 guided is to the position of action and tightly contacts therecording head 28. Then, a tube pump 233 is driven via the third gear109, generating negative pressure in the tightly closed space of therecording head 28. Accordingly, inks with high viscosity, which causeclogging in the nozzles of the recording head 28, are exhausted to thewaste liquid tank 40.

When the drive motor 38 is switched to the reverse rotation thereafter,the fourth gear 110 rotates in the direction opposite to the directionr1. This causes the driven gear 242 to rotate in the direction oppositeto the direction r2. The torque of the driven gear 242 is converted tofrictional force which is transmitted to the partially toothed gear 251so that the partially toothed gear 251 rotates in the direction oppositeto the direction r2 in a state where it does not engage with the fourthgear 110. At this time, the partially toothed gear 251 rotates until theprojection portion 260 abuts on the wall of the recess portion 259 inthe direction opposite to the direction r2, and then rotates togetherwith the first groove-forming member 255 and the second groove-formingmember 256. That is, the cylindrical cam 234 rotates in the directionopposite to the direction r2.

With the positioning member 262 a of the holding member 262 positionedin the third guide portion 252 c and the wiping member 263 being at theposition of action, the drive motor 38 is stopped. At this time, the capsupport member 47 is lowered by the elevation mechanism and the cap 46is positioned at the position of non-action so that the carriage 16becomes movable. Then, the recording apparatus 11 drives the carriagemotor 18 to move the carriage 16 in the direction opposite to thedirection of the arrow x from above the cap 46. Then, the carriage 16abuts on the wiping member 263 and moves in the direction opposite tothe direction of the arrow x so that the wiping member 263 is bent bythe carriage 16, which moves, and then its distal end 263 a abuts on therecording head 28. As the carriage 16 further moves in the direction ofthe arrow x, the wiping member 263 moves with respect to the recordinghead 28 and performs cleaning in such a way as to wipe the entiresurface of the recording head 28.

When the recording head 28 passes over the wiping member 263 andcleaning of the recording head 28 by the wiping member 263 is finishedin this way, the recording apparatus 11 rotates the drive motor 38reversely again. Therefore, the fourth gear 110 rotates again in thedirection opposite to the direction r1 and the driven gear 242 engagingwith the fourth gear 110 rotates in the direction opposite to thedirection r2 so that upon reception of the torque from the driven gear242, the partially toothed gear 251 rotates in the direction opposite tothe direction r2. The teeth 251 a of the partially toothed gear 251rotate to the position facing the fourth gear 110 to try to engage withthe fourth gear 110.

In the case where the teeth 242 a of the driven gear 242 are not alignedwith the teeth 251 a of the partially toothed gear 251 at this time,i.e., in the case where the teeth 251 a of the partially toothed gear251 do not smoothly engage with the teeth 110 a of the fourth gear 110,the teeth 251 a of the partially toothed gear 251 are filliped by thetorque of the teeth 110 a of the fourth gear 110. At this time, the loadof the partially toothed gear 251 is applied to the partially toothedgear 251 and the fourth gear 110. There is a gap between the projectionportion 260 of the partially toothed gear 251 and the recess portion 259of the second groove-forming member 256 and the large-diameter portion242 c of the driven gear 242 is fitted in the partially toothed gear251. Accordingly, even when the second groove-forming member 256 underthe partially toothed gear 251 and the driven gear 242 above thepartially toothed gear 251 are rotating, the partially toothed gear 251alone stops temporarily. That is, the partially toothed gear 51 rotatesin the direction r1 with respect to the driven gear 242, which isrotating in the direction opposite to the direction r1 always inengagement with the fourth gear 110, and the second groove-formingmember 256 which rotates due to inertial force.

Accordingly, only the partially toothed gear 251 stops temporarily andis so adjusted to smoothly engage with the teeth 110 a of the fourthgear 110. When the partially toothed gear 251 is aligned with the teeth242 a of the driven gear 242, it smoothly engages with the fourth gear110. Accordingly, the partially toothed gear 251 receives the torquefrom the fourth gear 110 via the tooth 251 a and the torque of thedriven gear 242 positioned above and rotates in the direction oppositeto the direction r1. As the cylindrical cam 234 rotates with therotation of the partially toothed gear 251, the positioning member 262 afitted in the third guide portion 252 c of the cam groove 252 movesalong the second guide portion 252 b of the cam groove 252 and is guidedto the first guide portion 252 a. Therefore, the wiping member 263 ofthe wiping apparatus 235 moves downward and the positioning member 262 areaches the first guide portion 252 a of the cam groove 252 as shown inFIGS. 16, 19, 20(a) and 21. The stop member 254 abuts on the first endportion 253 a of the rotation restriction groove 253, restricting therotation of the cylindrical cam 234, so that the cylindrical cam 234stops rotating in the direction opposite to the direction r1.Thereafter, the rotation of the drive motor 38 is stopped.

The present embodiment has the following advantages.

When the positioning member 262 a moves to the third guide portion 252 cfrom the first guide portion 252 a through the second guide portion 252b or moves to the first guide portion 252 a from the third guide portion252 c through the second guide portion 252 b, the partially toothed gear251 engages with the fourth gear 110 and receives drive force. Even ifinks are adhered to the partially toothed gear, increasing the load,therefore, the positioning member 262 a reliably receives the torquefrom the fourth gear 110 when moving to the second guide portion 252 b.It is therefore possible to reliably rotate the cylindrical cam 234 andensure the elevation of the wiping member 263.

The driven gear 242 provided above the partially toothed gear 251 ispressed toward the partially toothed gear 251 by the compression spring250, so that the torque of the driven gear 242 is converted tofrictional force and is transmitted to the partially toothed gear 251 bythe frictional force. Therefore, when the partially toothed gear 251,even disengaged from the fourth gear 110, is rotated reversely, thecylindrical cam 234 is rotated upon reception of rotation force from thedriven gear 242 and the partially toothed gear 251 tries to engage withthe fourth gear 110. At this time, the cylindrical cam 234 keepsreceiving the torque of the driven gear 242, so that when the partiallytoothed gear 251 does not smoothly engage with the fourth gear 110, thepartially toothed gear 251 stops regardless of the rotation of thesecond groove-forming member, which rotates upon reception of frictionalforce from the driven gear 242. That is, as the partially toothed gear251 rotates with respect to the second groove-forming member 256, thepartially toothed gear 251 can smoothly engage with the fourth gear 110with a small load.

The partially toothed gear 251 can turn by a gap (by one pitch a)between the recess portion 259 and the projection portion 260 withrespect to the second groove-forming member 256. With the partiallytoothed gear 251 not in smooth engagement with the fourth gear 110,therefore, the partially toothed gear 251 is filliped in accordance withthe rotation of the fourth gear 110 and the partially toothed gear 251moves with respect to the other members (first and second groove-formingmembers 255 and 256) of the cylindrical cam 234. Accordingly, the drivemotor 38 is stopped regardless of the movements of the firstgroove-forming member 255 and the second groove-forming member 256 andthe position of the teeth 251 a of the partially toothed gear 251 isadjusted in such a way that the partially toothed gear 251 engages withthe fourth gear 110 by the torque from the fourth gear 110. At thistime, the load of the partially toothed gear 251 alone, not the entireload of the cylindrical cam 234, is applied to the fourth gear 110.Therefore, the partially toothed gear 251 can be smoothly engaged withthe fourth gear 110 with a small load. As the partially toothed gear 251engages with the fourth gear 110 smoothly without a large load appliedto the partially toothed gear 251, therefore, the partially toothed gear251 can have an extended life.

As shown in FIG. 23, the ring-like partially toothed gear 251 becomeslighter as compared with a gear having, for example, a disk shape. It istherefore possible to make the load from the engagement of the partiallytoothed gear 251 with the fourth gear 110 smaller. The partially toothedgear 251 can thus be engaged with the fourth gear 110 smoothly and canbe made to have a longer life.

The partially toothed gear 251 is rotatable with respect to the drivengear 242. When the position of the tooth 251 a is adjusted to engage thepartially toothed gear 251 with the fourth gear 110, therefore, thepartially toothed gear 251 can be stopped irrespective of the rotationalstate of the driven gear 242. Thus, the load at the time the partiallytoothed gear 251 engages with the fourth gear 110 can be reduced.

As shown in FIG. 22, the gap between the projection portion 260 and therecess portion 259 is set to one pitch of the teeth 251 a of thepartially toothed gear 251, so that the partially toothed gear 251 canrotate by one pitch with respect to the second groove-forming member256. If the partially toothed gear 251 can rotate by at least one pitch,the teeth 251 a of the partially toothed gear 251, regardless of theposition, can be adjusted to engage with the teeth 110 a of the fourthgear 110. Because the gap between the projection portion 260 and therecess portion 259 becomes the rotational angle loss with respect to thesecond groove-forming member 256 of the partially toothed gear 251, itis better if the gap is smaller. By setting the gap between theprojection portion 260 and the recess portion 259 to one pitch of theteeth 251 a of the partially toothed gear 251, therefore, the rotationalangle loss can be minimized and the teeth 251 a of the partially toothedgear 251 can smoothly be engaged with the teeth 110 a of the fourth gear110 without applying a large load.

The partially toothed gear 251 of the cylindrical cam 234 can smoothlyengage with the fourth gear 110 with a small load and can reliablyrotate the cylindrical cam 234 upon reception of the drive force fromthe fourth gear 110. Therefore, the positioning member 262 a inserted inthe cam groove 252 formed in the cylindrical cam 234 can surely beguided to the individual guide portions 252 a, 252 b and 252 c toreliably carry out elevation of the wiper support member 261 over a longperiod of time. As a result, the recording head 28 can be wiped cleanreliably over a long period of time by the wiping member 263 and thenozzle protecting device 30 can carry out an adequate cleaning operationfor a long period of time.

As the nozzle protecting device 30 performs an adequate cleaningoperation for a long period of time, the recording head 28 can be keptin good condition over a long period of time. Therefore, the recordingapparatus 11 can discharge the individual inks from the ink cartridges21 and 22 at a predetermined timing and print a clear image.

As the projection portions 260 formed on the partially toothed gear 251are fitted in the recess portions 259 formed in the secondgroove-forming member 256, the partially toothed gear 251 is provided onthe cylindrical cam 234. Therefore, the partially toothed gear 251 canbe provided on the cylindrical cam 234 with a simple structure in such away that the partially toothed gear 251 is rotatable within apredetermined range with respect to the second groove-forming member256.

The cam groove 252 that guides the positioning member 262 a, whichdetermines the elevation position of the wiping member 263, in the upand down direction is formed on the cylindrical cam 234. It is thereforepossible to elevate the wiping member 263 via the positioning member 262a by the rotation of the cylindrical cam 234 with a simple structure.

The driven gear 242, which engages with the fourth gear 110 and rotatesabout the rotational axial center C, is provided in such a way as to bealigned with the partially toothed gear 251. This can reduce the spaceneeded for the arrangement of the driven gear 242. The fourth gear 110whose lower side engages with the partially toothed gear 251 and whoseupper side engages with the driven gear 242 has such a shape that theupper side and lower side have the same diameter. In other words, thefourth gear 110 need not be formed into a complex shape so that thestructure can be simplified.

The rotation restriction groove 253 of the cylindrical cam 234 restrictsthe cylindrical cam 234 in such a way that the cylindrical cam 234 doesnot rotate over a predetermined range. Even if the cylindrical cam 234receives, for example, the torque from the driven gear 242, therefore,it does not rotate over the predetermined range and malfunction. Even ifthe drive motor 38 keeps rotating to drive the tube pump 233, therefore,the wiper support member 261 can be elevated at a predetermined timing.

A fourth embodiment embodying the present invention will be describedbelow based on FIGS. 24 to 26. FIGS. 24 to 26 are bottom views forexplaining a partially toothed gear 271 according to this embodiment.

Like the partially toothed gear 251 in the embodiment in FIGS. 16 to 23,the partially toothed gear 271 having a ring-like shape is provided onthe second groove-forming member 256 of the cylindrical cam 234 in sucha way as to be aligned with the driven gear 242 and rotate about therotational axial center C. Teeth 271 a are formed on only about half thecircumferential surface of the partially toothed gear 271. The teeth 271a are formed at the same pitches a as the driven gear 242 and engagewith the fourth gear 110. The upper sides of the teeth 110 a of thefourth gear 110 engage with the teeth 242 a of the driven gear 242 andthe lower sides engage with the teeth 271 a of the partially toothedgear 271 at the same time.

Two cutaway portions 272 a and 272 b are formed on the circumferentialportion of the partially toothed gear 271 radially inward of the teeth271 a in such a way as to respectively correspond to both end portionsof the teeth 271 a (three teeth 271 a at both end portions). The cutawayportions 272 a and 272 b allow for bending of the three teeth 271 a inthe direction of the rotational axial center C of the partially toothedgear 271. Specifically, at the time the partially toothed gear 271engages with the fourth gear 110, when the threads of the teeth 110 a ofthe fourth gear 110 abut on the threads of the teeth 271 a, the cutawayportions 272 a and 272 b cause the teeth 271 a to be bent toward thecenter of the partially toothed gear 271.

The teeth 271 a which are positioned at the end portion E where theteeth 271 a of the partially toothed gear 271 shown in FIG. 24 areformed at such a position as to approximately face the fourth gear 110at the time the cleaning operation in which the stop member 254 abuts onthe end portion 253 a of the rotation restriction groove 253 starts.That is, as the fourth gear 110 rotates in the direction r1, the teeth271 a of the partially toothed gear 271 soon engages and the partiallytoothed gear 271 rotates in the direction r2.

The partially toothed gear 271 has two projection portions 273constructed like the projection portions 260 formed on the partiallytoothed gear 251 in the embodiment in FIGS. 16 to 23. Each projectionportion 273 engages with the associated recess portion 259 of the secondgroove-forming member 256. That is, the partially toothed gear 271 canrotate by the pitch a of the teeth 271 a with respect to the secondgroove-forming member 256 as per the embodiment in FIGS. 16 to 23.

With the above-described structure, the driven gear 242 is aligned withthe partially toothed gear 271 so that the driven gear 242 can rotatewith respect to the cylindrical cam 234 and rotates about the rotationalaxial center C of the cylindrical cam 234.

The action of the partially toothed gear 271 will be described next.

When the drive motor 38 is switched to the reverse rotation from thestate where the partially toothed gear 271 is not engaged with thefourth gear 110, the fourth gear 110 rotates in the direction oppositeto the direction r1, as shown in FIG. 24. Upon reception of the torquefrom the fourth gear 110 via the driven gear 242, the partially toothedgear 271 rotates in the direction opposite to the direction r2. Theteeth 271 a of the partially toothed gear 271 tries to rotate to theposition facing the fourth gear 110 and engage with it.

In the case where the threads of the partially toothed gear 271 at theposition facing the fourth gear 110 abut on the threads of the teeth 110a of the fourth gear 110 but are not in alignment at this time, theteeth 271 a are bent toward the rotational axial center C by the cutawayportion 272 b as shown in FIG. 25. With the rotation of the fourth gear110, the threads of the teeth 271 a and the threads of the teeth 110 awhich are in abutment with the teeth 271 a start shifting and the teeth271 a eventually engage with the teeth 110 a. And, the partially toothedgear 271 rotates in the direction opposite to the direction r2 as shownin FIG. 26.

As the teeth 271 a are bent by the cutaway portion 272 b, the partiallytoothed gear 271 can smoothly engage with the fourth gear 110.

The present embodiment has the following advantages in addition to theadvantages of the embodiment in FIGS. 16 to 23.

The two cutaway portions 272 a and 272 b are formed on thecircumferential portion of the partially toothed gear 271. They can bendthe teeth 271 a even if the threads of the teeth 271 a abut on thethreads of the teeth 110 a when the partially toothed gear 271 engageswith the fourth gear 110, thereby reducing the load on the partiallytoothed gear 271 and the fourth gear 110 so that smooth engagement cantake place. As a result, the partially toothed gear 271 and the fourthgear 110 can have longer lives. Further, the formation of the cutawayportions 272 a and 272 b can provide the teeth 271 a of the partiallytoothed gear 271 with flexibility without complicating the structure.

As the partially toothed gear 271 of the cylindrical cam 234 bends theteeth 271 a, it can engage with the fourth gear 110 smoothly with asmaller load, and with the engagement, the partially toothed gear 271can receive the drive force from the fourth gear 110 and reliably rotatethe cylindrical cam 234. It is therefore possible to surely guide thepositioning member 262 a inserted in the cam groove 252 formed in thecylindrical cam 234 to the individual guide portions 252 a, 252 b and252 c to reliably execute elevation of the wiper support member 261 overa long period of time. Consequently, the recording head 28 can reliablybe wiped clean with the wiping member 263 for a long period of time.Accordingly, the nozzle protecting device 30 can carry out an adequatecleaning operation for a long period of time.

A recording apparatus 311 according to a fifth embodiment of the presentinvention will be described below based on FIGS. 27 to 32. The recordingapparatus 311 in the present embodiment has an elevation mechanism whichelevates the guide member 15 and a cylindrical cam 334 which differs instructure from the cylindrical cam 234, as compared with the structureof the recording apparatus 11 in FIGS. 16 to 23.

As shown in FIG. 27, the recording apparatus 311 has a platen 313 whichextends in the direction of the arrow x and has a flat surface. Theplaten 313 is a support to support a target T, such as ordinary paper ora CD-ROM.

The recording apparatus 311 has an unillustrated thickness sensor in thevicinity of an unillustrated drive roller which is driven by the feedmotor 14. The thickness sensor detects whether the target T fed to therecording apparatus 311 is thick or not.

A support hole 320 a is formed in the carriage 16 provided in therecording apparatus 311 as shown in FIGS. 28( a) and 28(b). The guidemember 15 laid out in parallel to the timing belt 17 is inserted in thesupport hole 320 a. The carriage 16 reciprocates in the direction of thearrow x via the timing belt 17 by the driving of the carriage motor 18while being guided to the guide member 15.

Next, a guide mechanism 300 including the guide member 15 and theelevation mechanism for the guide member 15 are discussed based on FIGS.28( a) and 28(b). FIG. 28( a) shows the carriage 16 at a lower positionand FIG. 28( b) shows the carriage 16 lifted up to an upper position.

The guide mechanism 300 includes the guide member 15, an outer cylindermember 325 a fixed to the support hole 320 a of the carriage 16 and acenter shaft 326 rotatably supported on the outer cylinder member 325 a.Two eccentric shafts 327 eccentric to the axial center of the centershaft 326 are fixed to corresponding end portions of the guide member15. Both eccentric shafts 327 are rotatably supported on the frame 12(see FIG. 27). An actuation lever 328 is fixed to the right eccentricshaft 327. An actuation groove 328 a is formed in the actuation lever328.

A reversible motor M is secured to the frame 12 shown in FIG. 27. Thereversible motor M is driven based on a signal from the thickness sensoror the thickness of the target T. As shown in FIGS. 28( a) and 28(b),the proximal end of an arm lever 329 is fixed to the rotary shaft, Ma,of the reversible motor M. The arm lever 329 is rotatable along thedirection r. The arm lever 329 is coupled to the actuation groove 328 aof the actuation lever 328 slidably and rotatably. As the reversiblemotor M is rotated to turn the arm lever 329 along the direction r, botheccentric shafts 327 rotate and the center shaft 326 fixed to theeccentric shafts 327 rotates about the eccentric shafts 327 and arelowered. As a result, the carriage 16 is elevated, changing a distancePG1, PG2 from the platen 313 to the recording head 28.

As shown in FIG. 29, a cam groove 355 different in structure from thecam groove 252 of the cylindrical cam 234 in FIG. 16 is formed in thecircumferential surface of the cylindrical cam 334. The cam groove 355includes a retreat guide portion 356, an action guide portion 357 and astandby guide portion 358, as shown in FIG. 30. The retreat guideportion 356 extends along the circumferential direction at the lowermostportion of the cylindrical cam 334. The retreat guide portion 356 isformed in a range of angle, θ= about −9° to about 6°, provided that aline OC (see FIG. 21) connecting the center of the stop member 254 tothe rotational axial center C of the cylindrical cam 334 is 0°, as shownin FIG. 30.

As shown in FIG. 30, the action guide portion 357 is formed in a rangeof angle, θ=about 6° to about 56°. The action guide portion 357 has afirst inclined portion 357 a obliquely extending upward from the retreatguide portion 356, and a first position guide portion 357 b extendingalong the circumferential direction from the first inclined portion 357a. The first position guide portion 357 b is at the position of theangle, θ=about 25°. Further, the action guide portion 357 has a secondinclined portion 357 c obliquely extending upward from the firstposition guide portion 357 b, and a second position guide portion 357 dextending along the circumferential direction from the second inclinedportion 357 c. The second position guide portion 357 d is at theposition of the angle, θ=about 50°. When the cylindrical cam 334 isrotated about 25° in the direction r2 (see FIG. 21) from the positionshown in FIG. 30, therefore, the first position guide portion 357 breaches right above the stop member 254, and when the cylindrical cam334 is rotated about 50°, the second position guide portion 357 dreaches right above the stop member 254. That is, the action guideportion 357 has the first position guide portion 357 b and the secondposition guide portion 357 d as plural positions of action of differentheights.

The standby guide portion 358 is formed in a range of angle, θ=about 56°to about 200°. As the stop member 254 abuts on the portion 253 b of therotation restriction groove 253 of the cylindrical cam 334, the endportion of the standby guide portion 358 is positioned. That is, the camgroove 355 is formed in approximately the same range as the range wherethe rotation of the cylindrical cam 334 is restricted. The standby guideportion 358 includes a standby inclined portion 358 a obliquelyextending downward from the second position guide portion 357 d of theaction guide portion 357 and a standby portion 358 b extending along thecircumferential direction from the lower end of the standby inclinedportion 358 a.

As shown in FIG. 29, when the positioning member 262 a slides in theretreat guide portion 356 or the standby portion 358 b of the standbyguide portion 358, the positioning member 262 a is guided to theposition of non-action at the lowest position. When the positioningmember 262 a slides in the first position guide portion 357 b of theaction guide portion 357, the holding member 262 is guided to a firstposition of action. When the positioning member 262 a slides in thesecond position guide portion 357 d, the holding member 262 is guided toa second position of action higher than the first position of action.Further, when the positioning member 262 a slides in the first inclinedportion 357 a of the action guide portion 357, the holding member 262 isguided to the first position guide portion 357 b from the retreatposition. When the positioning member 262 a slides in the secondinclined portion 357 c of the action guide portion 357, the holdingmember 262 is guided to the second position guide portion 357 d from thefirst position guide portion 357 b. Further, when the holding member 262slides in the standby inclined portion 358 a of the standby guideportion 358, the holding member 262 is guided to the standby portion 358b of the standby guide portion 358 from the second position guideportion 357 d of the action guide portion 357.

When the stop member 254 abuts on the end portion 253 a of the rotationrestriction groove 253 of the cylindrical cam 334 (see FIG. 21), thepositioning member 262 a is positioned at the position where it abuts ona start end portion S of the retreat guide portion 356 of the cam groove355. In this state, the holding member 262 is positioned at the positionof non-action. When the fourth gear 110 is rotated in the direction r1from this state, the driven gear 242 and the partially toothed gear 251rotate in the direction r2. Accordingly, the cam groove 355 of thecylindrical cam 334 rotates and the positioning member 262 a slides tocontact the standby portion 358 b from the retreat guide portion 356 ofthe cam groove 355 through the first inclined portion 357 a, the firstposition guide portion 357 b, the second inclined guide portion 357 cand the second position guide portion 357 d of the action guide portion357 and the standby inclined portion 358 a of the standby guide portion358 in that order.

When the positioning member 262 a slides to contact the first inclinedportion 357 a of the action guide portion 357 toward the first positionguide portion 357 b, the wiper support member 261 is moved upward. Whenthe cylindrical cam 334 is rotated about 25°, the wiper support member261 reaches the first position of action where it slides to contact thefirst position guide portion 357 b. When the positioning member 262 aslides to contact the second inclined portion 357 c toward the secondposition guide portion 357 d from the first position guide portion 357b, the wiper support member 261 is moved upward. When the cylindricalcam 334 is rotated about 200°, the wiper support member 261 reaches thesecond position of action where it slides to contact the second positionguide portion 357 d.

When the cylindrical cam is rotated about 200° and the stop member 254abuts on the first end portion 253 b of the rotation restriction groove253, the positioning member 262 a abuts on the end portion E of thestandby portion 358 b of the standby guide portion 358 of the cam groove355. The partially toothed gear 251 engages with the fourth gear 110only in the range where the positioning member 262 a moves from theretreat guide portion 356 of the cam groove 355 to the standby guideportion 358 through the action guide portion 357.

As the drive motor 38 is rotated reversely, the positioning member 262 aslides to contact the retreat guide portion 356 from the standby guideportion 358 through the action guide portion 357 in reverse order to theabove-described order. When the stop member 254 is rotated about 150°from the state where the stop member 254 abuts on the end portion 253 bor the state where the positioning member 262 a is positioned at the endportion E of the standby portion 358 b, the positioning member 262 areaches the second position of action for the second position guideportion 357 d. When the positioning member 262 a is rotated about 175°from the state where it is positioned at the end portion E of thestandby portion 358 b, the positioning member 262 a reaches the firstposition of action for the first position guide portion 357 b.

As shown in FIG. 29, when the positioning member 262 a is positioned inthe retreat guide portion 356, the wiping member 263 is positioned atthe retreat position isolated from the recording head 28. When thepositioning member 262 a is positioned at the first position of actionfor the first position guide portion 357 b (see FIG. 28( a)), the platen313 is separated from the end face of the recording head 28 by thedistance PG1. At this time, as shown in FIG. 31, the distal end 263 a ofthe wiping member 263 is positioned above by a predetermined height Dfrom the line that extends from the end face of the recording head 28.Further, when the positioning member 262 a is positioned at the secondposition of action for the second position guide portion 357 d (see FIG.28( b)), the platen 313 is separated from the end face of the recordinghead 28 by the distance PG2. At this time, as shown in FIG. 32, thedistal end 263 a of the wiping member 263 is positioned above by thepredetermined height D from the line that extends from the end face ofthe recording head 28 as in the state in FIG. 31. The wiper positionadjusting means in this embodiment includes the cylindrical cam 334, theholding member 262 and the positioning member 262 a.

The action of the above-described recording apparatus 311 will bedescribed next.

When printing is carried out by the recording apparatus 311, first, thetarget T is led into the recording apparatus 311 by the feed motor 14.At this time, the thickness of the target T to be led is detected by thethickness sensor in the vicinity of the feed roller. Normally, therecording apparatus 311 is so set as to print on the relatively thintarget T such as normal paper. In the case where the recording apparatus311 determines that the relatively thin target T has been led, it keepsthe carriage 16 at a low position as shown in FIG. 28( a) withoutdriving the reversible motor M. That is, in this case, the recordingapparatus 311 prints with the setting of the distance PG1 from theplaten 313 to the recording head 28.

The recording apparatus 311 further drives the feed motor 14 to guidethe target T between the platen 313 and the recording head 28. Therecording apparatus 311 drives the piezoelectric element to eject inkssupplied from the ink cartridges 21 and 22 toward the target T from thenozzles of the recording head 28 while reciprocating the carriage 16along the direction x by driving the carrriage motor 18. When ejectionfrom the recording head 28 is finished within the range where thecarrriage 16 can reciprocate, the recording apparatus 311 drives thefeed motor 14 to feed the target T forward by a predetermined amount.Thereafter, the recording apparatus 311 drives the carriage motor 18 andthe piezoelectric element again to eject inks from the recording head 28while moving the carrriage 16. Printing on the target T is carried outby repeating these steps.

In the case where printing is finished and the cleaning operation forthe recording head 28 is to be carried out, the recording apparatus 311drives the carriage motor 18 to move the carriage 16 in the direction xto the position facing the cap 46. At this time, the positioning member262 a of the wiper support member 261 is positioned at the retreat guideportion 356 of the cam groove 355, as shown in FIG. 29. Even if thecarriage 16 passes over the wiping member 263 in the direction x, thedistal end 263 a of the wiping member 263 does not abut on the recordinghead 28 of the carriage 16. At this time, the stop member 254 abuts onthe first end portion 253 a of the rotation restriction groove 253 atthe bottom of the cylindrical cam 234 and the tooth 251 a positioned atthe end portion E of the partially toothed gear 251 faces the fourthgear 110.

When the carriage 16 reaches the position facing the cap 46, therecording apparatus 311 stops driving the carriage motor 18 and rotatesthe drive motor 38 forward. As the drive motor 38 is rotated forward,the drive gear 38 a rotates and the torque is transmitted to the fourthgear 110 via the first to third gears 107 to 109. Accordingly, thefourth gear 110 is rotated in the direction r1 and the driven gear 242which engages with the fourth gear 110 is rotated in the direction r2.As the teeth 251 a of the partially toothed gear 251 are at the positionfacing the fourth gear 110, the teeth 251 a of the partially toothedgear 251 engage with the fourth gear 110. This causes the cylindricalcam 234 to rotate in the direction r2, rotating the cam groove 355. As aresult, the positioning member 262 a reaches the standby guide portion358 from the retreat guide portion 356 of the cam groove 355 through theaction guide portion 357, elevating the wiping member 263.

When the positioning member 262 a reaches the standby guide portion 358and the cylindrical cam 234 makes about a half turn, the teeth 251 a ofthe partially toothed gear 251 do not engage with the fourth gear 110.As the driven gear 242 which slides in contact to the partially toothedgear 251 keeps rotating, however, the torque of the driven gear 242 isconverted to frictional force which is transmitted to the partiallytoothed gear 251, further rotating the cylindrical cam 234. And, whenthe stop member 254 abuts on the first end portion 253 b of the rotationrestriction groove 253 or rotates about 200°, the rotation of thecylindrical cam 234 in the direction r2 is stopped.

The cap support member 47 is elevated by the elevation mechanism whichis driven by the transmitted torque of the driven gear 242 and the cap46 guided to the position of action tightly closes the recording head28. Then, the tube pump 37 is driven via the third gear 109, generatingnegative pressure in the tightly-closed space of the recording head 28.Accordingly, high-viscosity inks, which would clog the nozzles of therecording head 28, are exhausted to the waste liquid tank 40.

When the drive motor 38 is switched to the reverse rotation thereafter,the fourth gear 110 is rotated in the direction opposite to thedirection r1. Accordingly, the cylindrical cam 234 is rotated in thedirection opposite to the direction r2 via the driven gear 242. When thepositioning member 262 a reaches the action guide portion 357 from thestandby guide portion 358 thereafter, the partially toothed gear 251engages with the fourth gear 110 also. When the cylindrical cam 234 isrotated about 175° in the direction opposite to the direction r2 fromthe end portion E of the standby portion 358 b of the standby guideportion 358, the drive motor 38 is stopped. Before the drive motor 38 isstopped, the partially toothed gear 251 engages with the fourth gear 110and further the positioning member 262 a reaches the first positionguide portion 357 b through the second position guide portion 357 d andthe second inclined guide portion 357 c of the cam groove 355.

When the cylindrical cam 234 is stopped at the position of 25° rotationsince the beginning of cleaning, as shown in FIG. 31, the positioningmember 262 a is positioned at the standby guide portion 358.Accordingly, the wiping member 263 is placed at the first position ofaction. This causes the distal end of the wiping member 263 to bepositioned above the recording head 28 by the predetermined height D.

The cap support member 47 is lowered by the elevation mechanism and thecap 46 is positioned at the position of non-action so that the carriage16 becomes movable. The recording apparatus 311 drives the carriagemotor 18 to move the carriage 16 in the direction of the arrow x fromabove the cap 46. Then, the carriage 16 abuts on the wiping member 263and moves in the direction opposite to the direction x, so that thewiping member 263 is bent by the moving carriage 16 and its distal end263 a abuts on the recording head 28. The further movement of thecarriage 16 causes the wiping member 263 to move with respect to therecording head 28 and perform wipe and cleaning to wipe off the entiresurface of the recording head 28.

When cleaning of the recording head 28 by the wiping member 263 isfinished, the recording apparatus 311 reversely rotates the drive motor38 again. Therefore, the fourth gear 110 is rotated in the directionopposite to the direction r1 again so that the driven gear 242 and thepartially toothed gear 251 rotate in the direction opposite to thedirection r2. Therefore, the cylindrical cam 234 rotates in thedirection opposite to the direction r2. Accordingly, the positioningmember 262 a reaches the retreat guide portion 356 through the firstinclined portion 357 a of the action guide portion 357. As thecylindrical cam 234 is rotated to the position at which cleaning starts(see FIG. 21), the stop member 254 abuts on the first end portion 253 aof the rotation restriction groove 253. This restricts the rotation ofthe cylindrical cam 234 so that the cylindrical cam 234 stops rotatingin the direction opposite to the direction r1 and stops. Thereafter, therotation of the drive motor 38 is stopped.

Next, a case where printing is done on the thick target T such as aCD-ROM in place of normal paper will be described. When the target T isled by the feed motor 14, the thickness sensor in the recordingapparatus 311 detects the thickness of the target. When the recordingapparatus 311 determines that the target is thicker than a predeterminedvalue, the recording apparatus 311 drives the reversible motor M torotate the arm lever 329. Accordingly, the carriage 16 comes to thestate in FIG. 28( b) where it is lifted by a height H from the state inFIG. 28( a). That is, the distance PG1 from the platen 313 to therecording head 28 is changed to the distance PG2 greater than thedistance PG1.

Thereafter, at the time the drive motor 38 is rotated forward and thenrotated reversely in the cleaning operation, the carriage 16 is at anupper position, so that the drive motor 38 temporarily stops after beingrotated 150°, not 175°, from the end wall of the standby portion 358 bof the standby guide portion 358. That is, it temporarily stops in astate where it is rotated by the angle, θ=50° (see FIG. 21).

As shown in FIG. 32, the positioning member 262 a is positioned at thesecond position guide portion 357 d of the cam groove 355, the holdingmember 262 is guided to the second position of action and the end faceof the distal end 263 a of the wiping member 263 projects out from theline extending from the end face of the recording head 28 by thepredetermined height D. Even when the distance PG1 (see FIG. 28( a))from the platen 313 to the recording head 28 is changed to the distancePG2 (see FIG. 28( b)), therefore, a distance D from the end face of thedistal end 263 a of the wiping member 263 to the recording head 28 isalways constant and the wiping member 263 performs wiping and cleaningin this state.

If the thin target T is led to the recording apparatus 311 to performprinting on the target T, the thickness is detected by the thicknesssensor and the reversible motor M coupled to the arm lever 329 isrotated reversely. Accordingly, the recording head 28 is lowered to theposition shown in FIG. 28( a) from the position shown in FIG. 28( b). Inthe case where cleaning is carried out in this state, the drive motor 38rotated forward temporarily stops in the state where it is rotated 175°from the end wall of the standby portion 358 b. With the distal end 263a of the wiping member 263 always positioned above the end face of therecording head 28 by the predetermined height D, the wiping member 263wipes the recording head 28 clear.

The present embodiment has the following advantages.

As shown in FIGS. 28( a) and 28(b), the elevation position of the wipingmember 263 is changed according to the distance PG1, PG2 from the platen313 to the end face of the recording head 28. Even when the recordinghead 28 is elevated and the distance PG1, PG2 is changed, however, thedistal end 263 a of the wiping member 263 is always placed above the endface of the recording head 28 by the same height D. This can make theinterference portion of the wiping member 263 with respect to therecording head 28 constant, so that the wiping member 263 can alwaysadequately wipe the recording head 28 clear. Therefore, the recordinghead 28 can always eject inks that are in a good condition.

The positioning member 262 a which is guided in the up and downdirection as it slides in the cam groove 355 formed in the cylindricalcam 234 is coupled to the holding member 262 which supports the wipingmember 263. Accordingly, as the cylindrical cam 234 rotates, thepositioning member 262 a slides in the cam groove 355, elevating thewiping member 263. The position of the wiping member 263 can thereforebe adjusted easily with a simple structure.

As shown in FIGS. 28( a) and 28(b), each distance PG1, PG2 from theplaten 313 to the recording head 28 is adjusted by elevating therecording head 28. That is, because the carriage 16 alone is elevated,each distance PG1, PG2 from the platen 313 to the recording head 28 canbe adjusted easily without applying a large load.

The cam groove 355 has the retreat guide portion 356 which does not abuton the carriage 16 even if the carriage 16 passes above, the firstposition guide portion 357 b at which the holding member 262 is set atthe first position of action and the second position guide portion 357 dat which the holding member 262 is set at the second position of action.With the positioning member 262 a positioned at the retreat guideportion 356 and the wiping member 263 at the retreat position isolatedfrom the recording head 28, the recording head 28 passes over the wipingmember 263, so that the wiping member 263 does not receive force fromthe recording head 28. Accordingly, unnecessary force is not applied tothe wiping member 263, thus making it possible to extend its life.

The cam groove 355 has the horizontal portion where the first positionguide portion 357 b and the second position guide portion 357 d areformed on the circumferential surface of the cylindrical cam 234. Thatis, the first and second position guide portions 357 b and 357 d forpositioning the wiping member 263 are the horizontal portion of apredetermined length. Even if there is an error in the rotational angleat which the cylindrical cam 234 temporarily stops, therefore, theposition of the wiping member 263 is elevated to a predetermined height.That is, the wiping member 263 can be adjusted to a predeterminedposition even if the rotation of the cylindrical cam 234 is not strictlycontrolled to stop.

Only the wiping apparatus 235 which is a part of the nozzle protectingdevice 30 is elevated based on each distance PG1, PG2. This makes itpossible to easily elevate the wiping member 263 with a smaller load ascompared with elevation of the entire nozzle protecting device 30.

As the recording apparatus 311 automatically discriminates the thicknessof the target T to be led out, each distance PG1, PG2 from the platen313 to the recording head 28 as well as the position of the wipingmember 263 is adjusted. This can allow the wiping member 263 toadequately wipe the recording head 28 clear and can make it unnecessaryto adjust the distance PG1, PG2 on the user side, so that inks can beejected to the target T more adequately.

Next, a sixth embodiment of the present invention will be describedbased on FIG. 33. This embodiment differs from the embodiment in FIGS.27 to 32 only in the shape of the cam groove 355 and the same symbols aswith the embodiment in FIGS. 27 to 32 are used with similar portions andtheir detailed descriptions are omitted.

A cam groove 455 in this embodiment has a retreat guide portion 466positioned below the cylindrical cam 234, an action guide portion 467obliquely extending upward from the retreat guide portion 466 and astandby guide portion 468 extending along the circumferential directionfrom the action guide portion 467. The action guide portion 467 isstraight. The action guide portion 467 becomes the same height as thefirst position guide portion 357 b in FIG. 30 when rotated by an angle,θ=25° and becomes the same height as the second position guide portion357 d in FIG. 30 when rotated by 50°. That is, if the drive motor 38 istemporarily stopped at a rotational angle similar to that in theembodiment in FIGS. 27 to 32 when the drive motor 38 rotates reversely,the holding member 262 is placed at the first position of action or thesecond position of action via the positioning member 262 a inserted inthe cam groove 455. In the present embodiment, the standby guide portion468 is formed at an upper position. When the positioning member 262 a ispositioned at the standby guide portion 468, the carriage 16 moves tothe position facing the cap 46 and does not pass over the wiping member263 so that the wiping member 263 is not subjected to force from therecording head 28.

The present embodiment has the following advantages below in addition tothe advantages, such as the recording head always ejecting inks or easyadjustment of the position of the wiper member.

The cam groove 455 includes the retreat guide portion 466 extending inthe circumferential direction, and the standby guide portion 468 and theaction guide portion 467, which connects them in a straight line. Thatis, because the cam groove 455 has a simpler shape as compared with thecam groove 355 in the embodiment in FIGS. 27 to 32, the cam groove 455can be formed easily.

The action guide portion 467 which determines the position of action ofthe positioning member 262 a is inclined to be straight. This makes itpossible to easily adjust the position at which the cylindrical cam 234temporarily stops or the rotational angle of the drive motor 38 at thetime the wiping member 263 wipes the recording head 28 clean. Therefore,the optimal position at which the wiping member 263 wipes the recordinghead 28 clean can be acquired merely by a simple operation of delicatelyadjusting the rotational angle of the drive motor 38.

The above-described embodiments of the present invention may be modifiedas follows.

In the embodiment in FIGS. 1 to 11, if the inside of the cap 46 can beopened to and blocked from air by changing the relative distance betweenthe cap 46 and the cap support member 47, other air release means may beused as well.

In the embodiments in FIGS. 1 to 15, the valve body 58, 126 may also beformed of a flexible material. The valve body 58, 126 may alone beformed of a flexible material. Further, both the valve seat 56, 123 andthe valve body 58, 126 may be formed of a material other than a flexiblematerial.

In the embodiment in FIGS. 1 to 11, if the valve seat 56 and the valvebody 58 can abut on and part from each other by changing the relativedistance between the cap 46 and the cap support member 47, the valveseat 56 and the valve body 58 may be provided on other walls of the cap46.

In the embodiment in FIGS. 1 to 11, the valve body 58 may be urged in adirection to abut on the valve seat 56 by the spring member 58 a andother urging means. The valve seat 56 and the valve body 58 may be madeto abut on each other without using the spring member 58 a but by othermeans. In the embodiment in FIGS. 12 to 15, likewise, the valve body 126may be urged in a direction to abut on the valve seat 123 by the springmember 125 and other urging means. The valve seat 123 and the valve body126 may be made to abut on each other without using the spring member125 but by other means.

In the embodiment in FIGS. 1 to 11, when the relative distance betweenthe cap support member 47 and the cap 46 is maximum, the lever 73 may bepositioned within the movable range of the plate 61 or above the plate61. As a result, when the lever 73 is lifted upward, the plate 61 ispositioned under the lever 73 so that the plate 61 does not interferewith the elevation of the lever 73. Because it is unnecessary to slidethe lever 73 to lift the lever 73 upward, the apparatus can besimplified.

In the embodiment in FIGS. 1 to 11, for example, the contact surfaces ofthe plate 61 and the lever 73 may be set curved surfaces so that thelever 73 slides.

In the embodiment in FIGS. 1 to 11, the lever 73 may be urged in theslide direction by the spring member 77 and other urging means.

In the individual embodiments in FIGS. 1 to 15, if the cap supportmember 47, 121 can be moved up and down, the drive force from the drivemotor 38 may be transmitted via other transmission means in place of thecylindrical cam 35.

In the individual embodiments in FIGS. 1 to 15, the cylindrical cam 35is not restrictive, but other cams, e.g., a spherical cam, a conicalcam, a flat-plate cam or the like, may be used.

In the individual embodiments in FIGS. 1 to 15, instead of transmittingthe drive force from the drive motor 38 to the cylindrical cam 35 andthe tube pump 37 with a predetermined phase difference, they may bedriven by separate drive means respectively.

In the individual embodiments in FIGS. 1 to 15, the liquid ejectionapparatus may be an apparatus which ejects other liquids as well as aprinting apparatus including a facsimile or a copying machine. Forexample, it may be a liquid ejection apparatus, which ejects liquids forthe electrode materials or color materials to be used in manufacturing aliquid crystal display, an EL display, a surface emission display (FED)or the like, a liquid ejection apparatus, which ejects a living organicmaterial to be used in a bio chip, or a sample ejection apparatus, suchas a fine pipette.

In the embodiment in FIGS. 12 to 15, other air release means may be usedif the inside of the cap 120 can be opened and closed to air by changingthe distance between the cap support member 121 and the partition 133.

In the embodiment in FIGS. 12 to 15, the air tube 122 may be attached tothe other wall of the cap support member 121 other than by that whichlies on the third retaining portion 43 side and further, the valve body126 may likewise be attached to the same wall in such a way as torotatably abut on the valve seat 123. Accordingly, the partition 133should be provided in such a way that its abutment portion 134 abuts onthe projection 129 of the valve body 126.

In the embodiment in FIGS. 12 to 15, air in the cap 120 has only to benon-released by causing the valve body 126 to abut on the opening of thevalve seat 123. In the case where the opening of the valve seat 123 ison the left-hand side, for example, the valve body 126 may be providedto the left to the opening, and in the case where the opening of thevalve seat 123 is on the upper side, the valve body 126 may be providedon the upper side. At this time, the position of the abutment portion134 may be changed adequately.

In the embodiment in FIGS. 16 to 23, for example, the cam groove 252 maybe formed in the cylindrical cam 234 and the two members, the firstgroove-forming member 255 and the second groove-forming member 256, maybe formed by a single member.

In the individual embodiments in FIGS. 16 to 33, the partially toothedgear 251 may be provided on a portion other than the upper side of thecylindrical cam 234, e.g., on the lower side.

In the individual embodiments in FIGS. 16 to 33, the gap at the time theprojection portions 260 of the partially toothed gear 251 are insertedin the recess portions 259 of the second groove-forming member 256 maybe set to other than one pitch. If the gap is smaller than one pitch,engagement can be done more smoothly than in the prior art and therotational loss with respect to the cylindrical cam 234 of the partiallytoothed gear 251 can be reduced.

In the individual embodiments in FIGS. 16 to 33, recess portions may beformed in the partially toothed gear 251 and projection portions whichare fitted in the recess portions may be formed on the secondgroove-forming member 256.

In the individual embodiments in FIGS. 16 to 33, the diameters of thepartially toothed gear 251 and the driven gear 242 may differ from eachother. In this case, with regard to the lower side of the fourth gear110 with which the partially toothed gear 251 engages and the upper sideof the fourth gear 110 with which the driven gear 242 engage, two gearsof different diameters may be aligned with each other and placed as thefourth gear 110.

In the individual embodiments in FIGS. 16 to 33, the partially toothedgear 251, the fourth gear 110 and the driven gear 242 may be constitutedby a gear other than a spur gear, for example, a helical gear.

In the individual embodiments in FIGS. 16 to 33, the cylindrical cam234, 334 provided on the partially toothed gear 251 may be used in amechanism other than the one which elevates the wiping member 263. Forexample, the cylindrical cam 234, 334 may be used in an unillustratedmechanism which elevates the cap support member 47 so that the cap 46 iselevated by rotating the cylindrical cam 234, 334.

In the individual embodiments in FIGS. 27 to 33, the second position ofaction may be provided at a position close to the retreat guide portion356 which becomes the lowest portion at the time cleaning starts, andthe first position of action lower than the second position of actionmay be provided at a position close to the standby guide portion 358.

In the embodiment in FIGS. 27 to 32, more position guide portions 357 b,357 d which become the horizontal portions of the action guide portion357 may be provided. In the embodiment in FIG. 33, the timing ofstopping the drive motor 38 when rotated reversely may be adjustedaccurately. This can allow the wiping member 263 to always project fromthe end face of the recording head 28 by the predetermined height D evenwhen the distance PG1 (PG2) between the platen 313 and the recordinghead 28 is continuously adjustable.

In the individual embodiments in FIGS. 27 to 33, each distance PG1, PG2may be changed by elevation of the platen 313 instead of the recordinghead 28.

In the individual embodiments in FIGS. 27 to 33, each standby guideportion 358, 468 of the cam groove 355, 455 may be changed. As thepositioning member 262 a slides when the recording head 28 faces the cap46, both standby guide portions 358 and 468 do not receive force fromthe recording head 28 regardless of the height of the wiping member 263.

1. A liquid ejection apparatus comprising: a liquid ejection headincluding nozzles, a cap, a cap support member which supports said cap,and drive means for driving said cap support member to move said captoward the liquid ejection head and cover nozzles of said liquidejection head with said cap; elastic means which is intervened betweensaid cap support member and said cap and said elastic means stretchesfor changing a distance between said cap support member and said capwith said cap covering said nozzles; and air release means for openingand closing the inside of said cap with respect to air with said capcovering said nozzles in accordance with a change in said distance. 2.The liquid ejection apparatus according to claim 1, further comprising acam, where said cap support member is moved via the cam by said drivemeans.
 3. The liquid ejection apparatus according to claim 2, furthercomprising suction means for sucking a fluid from inside said cap,wherein said drive means drives said suction means with a predeterminedphase difference with respect to said cam.
 4. A liquid ejectionapparatus comprising: a liquid ejection head including nozzles, a cap, acap support member which supports said cap, and drive means for drivingsaid cap support member to move said cap toward the liquid ejection headand cover nozzles of said liquid ejection head with said cap; elasticmeans which is intervened between said cap support member and said capfor changing a distance between said cap support member and said cap bysaid elastic means stretching; and air release means for opening andclosing the inside of said cap covering said nozzles with respect to airin accordance with a change in said distance, wherein said air releasemeans includes: a through hole penetrating a wall of said cap; a valveseat provided integrally with said cap in such a way as to be positionedat an end portion of said through hole; a valve body provided integrallywith said cap; and a pressing member which is provided on said capsupport member and presses said valve body in accordance with a changein said distance between said cap support member and said cap, andpressure from said pressing member causes said valve body to move andselectively abut on and part from said valve seat, so that the inside ofsaid cap is opened and closed with respect to air via said through hole.5. The liquid ejection apparatus according to claim 4, wherein saidvalve seat is formed of a flexible material.
 6. The liquid ejectionapparatus according to claim 4, wherein said valve body is formed of aflexible material.
 7. The liquid ejection apparatus according claim 4,wherein said valve seat is provided at a lower side of said cap, saidvalve body is provided under said valve seat at a normal position, saidvalve body abuts on said valve seat to close said through hole whenmoving above said normal position, said valve body parts from said valveseat to open said through hole when moving below said normal position,said pressing member is positioned above said valve body when saiddistance between said cap support member and said cap is closest, andsaid pressing member presses said valve body downward from above whensaid distance between said cap support member and said cap increases. 8.The liquid ejection apparatus according to claim 7, wherein said valvebody includes urging means for urging said valve body in a direction toabut on said valve seat.
 9. The liquid ejection apparatus according toclaim 7, wherein said valve body is rotatable with respect to said cap,and said pressing member is positioned outside a movable range of saidvalve body when said distance between said cap support member and saidcap is a maximum.
 10. The liquid ejection apparatus according to claim9, wherein an inclined surface inclined relative to a movement directionof said cap support member is formed on a bottom side of said valve bodyand a top side of said pressing member.
 11. The liquid ejectionapparatus according to claim 7, wherein said pressing member issupported on said cap support member in such a way as to be slidable ina direction orthogonal to an opening or closing direction of said valvebody.
 12. The liquid ejection apparatus according to claim 11, whereinsaid pressing member includes urging means for urging said pressingmember in said slide direction.
 13. A liquid ejection apparatuscomprising: a liquid ejection head including nozzles, a cap, a capsupport member which supports said cap, and drive means for driving saidcap support member to move said cap toward the liquid ejection head andcover nozzles of said liquid ejection head with said cap; elastic meanswhich is intervened between said cap support member and said cap forchanging a distance between said cap support member and said cap by saidelastic means stretching; and air release means for opening and closingthe inside of said cap covering said nozzles with respect to air inaccordance with a change in said distance, wherein said air releasemeans includes: a through hole penetrating a wall of said cap; a tube tobe coupled to said through hole and having a distal end and a proximalend which is supported on said cap support member; a valve seat providedat said tube; a valve body provided at said cap support member; aretaining portion which retains said cap support member; and a pressingmember which is provided in said retaining portion and presses saidvalve body in accordance with a change in said distance between said capsupport member and said cap, and pressure from said pressing membercauses said valve body to move and selectively abut on and part fromsaid valve seat, so that the inside of said cap is opened and closedwith respect to air via said through hole.
 14. The liquid ejectionapparatus according to claim 13, wherein said valve seat is formed of aflexible material.
 15. The liquid ejection apparatus according claim 14,further comprising urging means for urging said valve body in adirection to abut on said valve seat.
 16. The liquid ejection apparatusaccording to claim 14, wherein said valve body is rotatable with respectto said cap support member, and said pressing member is positionedoutside a movable range of said projection of said valve body when saiddistance between said cap support member and said cap is a maximum. 17.The liquid ejection apparatus according to claim 13, wherein said valvebody is formed of a flexible material.
 18. The liquid ejection apparatusaccording to claim 13, wherein said valve body has a projectionabuttable on said pressing member, said through hole is closed when saidvalve body abuts on said valve seat, said through hole is opened whensaid valve body parts from said valve seat, said pressing member ispositioned below said valve body when said distance between said capsupport member and said cap is closest, and said pressing member pressessaid projection of said valve body upward from below to move said valvebody in a direction opposite to said valve seat when said distancebetween said cap support member and said cap increases.